Documentation/release/dev/update-fast_float-8.0.2.md

+## Update fast_float to be based on 8.0.2
+
+Update fast_float third party library to be based
+on [fast_float 8.0.2](https://github.com/fastfloat/fast_float/releases/tag/v8.0.2).

ThirdParty/fast_float/CMakeLists.txt

@@ -7,9 +7,9 @@ vtk_module_third_party(
     SPDX_COPYRIGHT_TEXT
       "Copyright (c) 2021 The fast_float authors"
     SPDX_DOWNLOAD_LOCATION
-      "git+https://gitlab.kitware.com/third-party/fast_float.git@for/vtk-20230309-3.9.0"
+      "git+https://gitlab.kitware.com/third-party/fast_float.git@for/vtk-20250313-8.0.2"
     VERSION
-      "3.9.0"
+      "8.0.2"
     STANDARD_INCLUDE_DIRS
     HEADER_ONLY
   EXTERNAL

ThirdParty/fast_float/update.sh

@@ -8,7 +8,7 @@ readonly name="fast_float"
 readonly ownership="fast_float Upstream <kwrobot@kitware.com>"
 readonly subtree="ThirdParty/$name/vtk$name"
 readonly repo="https://gitlab.kitware.com/third-party/fast_float.git"
-readonly tag="for/vtk-20230309-3.9.0"
+readonly tag="for/vtk-20250313-8.0.2"
 readonly paths="
 include/fast_float/*
 .gitattributes

ThirdParty/fast_float/vtkfast_float/CMakeLists.txt

@@ -3,12 +3,12 @@ vtk_module_install_headers(
   FILES
     vtkfast_float/ascii_number.h
     vtkfast_float/bigint.h
+    vtkfast_float/constexpr_feature_detect.h
     vtkfast_float/decimal_to_binary.h
     vtkfast_float/digit_comparison.h
     vtkfast_float/fast_float.h
     vtkfast_float/fast_table.h
     vtkfast_float/float_common.h
     vtkfast_float/parse_number.h
-    vtkfast_float/simple_decimal_conversion.h
     vtkfast_float/vtkfast_float_mangle.h
   )

ThirdParty/fast_float/vtkfast_float/CONTRIBUTORS

@@ -4,3 +4,8 @@ Marcin Wojdyr
 Neal Richardson
 Tim Paine
 Fabio Pellacini
+Lénárd Szolnoki
+Jan Pharago
+Maya Warrier
+Taha Khokhar
+Anders Dalvander

ThirdParty/fast_float/vtkfast_float/vtkfast_float/bigint.h

@@ -37,58 +37,58 @@ constexpr size_t bigint_limbs = bigint_bits / limb_bits;
 
 // vector-like type that is allocated on the stack. the entire
 // buffer is pre-allocated, and only the length changes.
-template <uint16_t size>
-struct stackvec {
+template <uint16_t size> struct stackvec {
   limb data[size];
   // we never need more than 150 limbs
   uint16_t length{0};
 
   stackvec() = default;
-  stackvec(const stackvec &) = delete;
-  stackvec &operator=(const stackvec &) = delete;
+  stackvec(stackvec const &) = delete;
+  stackvec &operator=(stackvec const &) = delete;
   stackvec(stackvec &&) = delete;
   stackvec &operator=(stackvec &&other) = delete;
 
   // create stack vector from existing limb span.
-  stackvec(limb_span s) {
+  FASTFLOAT_CONSTEXPR20 stackvec(limb_span s) {
     FASTFLOAT_ASSERT(try_extend(s));
   }
 
-  limb& operator[](size_t index) noexcept {
+  FASTFLOAT_CONSTEXPR14 limb &operator[](size_t index) noexcept {
     FASTFLOAT_DEBUG_ASSERT(index < length);
     return data[index];
   }
-  const limb& operator[](size_t index) const noexcept {
+
+  FASTFLOAT_CONSTEXPR14 const limb &operator[](size_t index) const noexcept {
     FASTFLOAT_DEBUG_ASSERT(index < length);
     return data[index];
   }
+
   // index from the end of the container
-  const limb& rindex(size_t index) const noexcept {
+  FASTFLOAT_CONSTEXPR14 const limb &rindex(size_t index) const noexcept {
     FASTFLOAT_DEBUG_ASSERT(index < length);
     size_t rindex = length - index - 1;
     return data[rindex];
   }
 
   // set the length, without bounds checking.
-  void set_len(size_t len) noexcept {
+  FASTFLOAT_CONSTEXPR14 void set_len(size_t len) noexcept {
     length = uint16_t(len);
   }
-  constexpr size_t len() const noexcept {
-    return length;
-  }
-  constexpr bool is_empty() const noexcept {
-    return length == 0;
-  }
-  constexpr size_t capacity() const noexcept {
-    return size;
-  }
+
+  constexpr size_t len() const noexcept { return length; }
+
+  constexpr bool is_empty() const noexcept { return length == 0; }
+
+  constexpr size_t capacity() const noexcept { return size; }
+
   // append item to vector, without bounds checking
-  void push_unchecked(limb value) noexcept {
+  FASTFLOAT_CONSTEXPR14 void push_unchecked(limb value) noexcept {
     data[length] = value;
     length++;
   }
+
   // append item to vector, returning if item was added
-  bool try_push(limb value) noexcept {
+  FASTFLOAT_CONSTEXPR14 bool try_push(limb value) noexcept {
     if (len() < capacity()) {
       push_unchecked(value);
       return true;
@@ -96,14 +96,16 @@ struct stackvec {
       return false;
     }
   }
+
   // add items to the vector, from a span, without bounds checking
-  void extend_unchecked(limb_span s) noexcept {
-    limb* ptr = data + length;
-    ::memcpy((void*)ptr, (const void*)s.ptr, sizeof(limb) * s.len());
+  FASTFLOAT_CONSTEXPR20 void extend_unchecked(limb_span s) noexcept {
+    limb *ptr = data + length;
+    std::copy_n(s.ptr, s.len(), ptr);
     set_len(len() + s.len());
   }
+
   // try to add items to the vector, returning if items were added
-  bool try_extend(limb_span s) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool try_extend(limb_span s) noexcept {
     if (len() + s.len() <= capacity()) {
       extend_unchecked(s);
       return true;
@@ -111,22 +113,25 @@ struct stackvec {
       return false;
     }
   }
+
   // resize the vector, without bounds checking
   // if the new size is longer than the vector, assign value to each
   // appended item.
+  FASTFLOAT_CONSTEXPR20
   void resize_unchecked(size_t new_len, limb value) noexcept {
     if (new_len > len()) {
       size_t count = new_len - len();
-      limb* first = data + len();
-      limb* last = first + count;
+      limb *first = data + len();
+      limb *last = first + count;
       ::std::fill(first, last, value);
       set_len(new_len);
     } else {
       set_len(new_len);
     }
   }
+
   // try to resize the vector, returning if the vector was resized.
-  bool try_resize(size_t new_len, limb value) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool try_resize(size_t new_len, limb value) noexcept {
     if (new_len > capacity()) {
       return false;
     } else {
@@ -134,10 +139,11 @@ struct stackvec {
       return true;
     }
   }
+
   // check if any limbs are non-zero after the given index.
   // this needs to be done in reverse order, since the index
   // is relative to the most significant limbs.
-  bool nonzero(size_t index) const noexcept {
+  FASTFLOAT_CONSTEXPR14 bool nonzero(size_t index) const noexcept {
     while (index < len()) {
       if (rindex(index) != 0) {
         return true;
@@ -146,29 +152,30 @@ struct stackvec {
     }
     return false;
   }
+
   // normalize the big integer, so most-significant zero limbs are removed.
-  void normalize() noexcept {
+  FASTFLOAT_CONSTEXPR14 void normalize() noexcept {
     while (len() > 0 && rindex(0) == 0) {
       length--;
     }
   }
 };
 
-fastfloat_really_inline
-uint64_t empty_hi64(bool& truncated) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 uint64_t
+empty_hi64(bool &truncated) noexcept {
   truncated = false;
   return 0;
 }
 
-fastfloat_really_inline
-uint64_t uint64_hi64(uint64_t r0, bool& truncated) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 uint64_t
+uint64_hi64(uint64_t r0, bool &truncated) noexcept {
   truncated = false;
   int shl = leading_zeroes(r0);
   return r0 << shl;
 }
 
-fastfloat_really_inline
-uint64_t uint64_hi64(uint64_t r0, uint64_t r1, bool& truncated) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 uint64_t
+uint64_hi64(uint64_t r0, uint64_t r1, bool &truncated) noexcept {
   int shl = leading_zeroes(r0);
   if (shl == 0) {
     truncated = r1 != 0;
@@ -180,20 +187,20 @@ uint64_t uint64_hi64(uint64_t r0, uint64_t r1, bool& truncated) noexcept {
   }
 }
 
-fastfloat_really_inline
-uint64_t uint32_hi64(uint32_t r0, bool& truncated) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 uint64_t
+uint32_hi64(uint32_t r0, bool &truncated) noexcept {
   return uint64_hi64(r0, truncated);
 }
 
-fastfloat_really_inline
-uint64_t uint32_hi64(uint32_t r0, uint32_t r1, bool& truncated) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 uint64_t
+uint32_hi64(uint32_t r0, uint32_t r1, bool &truncated) noexcept {
   uint64_t x0 = r0;
   uint64_t x1 = r1;
   return uint64_hi64((x0 << 32) | x1, truncated);
 }
 
-fastfloat_really_inline
-uint64_t uint32_hi64(uint32_t r0, uint32_t r1, uint32_t r2, bool& truncated) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 uint64_t
+uint32_hi64(uint32_t r0, uint32_t r1, uint32_t r2, bool &truncated) noexcept {
   uint64_t x0 = r0;
   uint64_t x1 = r1;
   uint64_t x2 = r2;
@@ -204,16 +211,17 @@ uint64_t uint32_hi64(uint32_t r0, uint32_t r1, uint32_t r2, bool& truncated) noe
 // we want an efficient operation. for msvc, where
 // we don't have built-in intrinsics, this is still
 // pretty fast.
-fastfloat_really_inline
-limb scalar_add(limb x, limb y, bool& overflow) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 limb
+scalar_add(limb x, limb y, bool &overflow) noexcept {
   limb z;
-
 // gcc and clang
 #if defined(__has_builtin)
-  #if __has_builtin(__builtin_add_overflow)
+#if __has_builtin(__builtin_add_overflow)
+  if (!cpp20_and_in_constexpr()) {
     overflow = __builtin_add_overflow(x, y, &z);
     return z;
-  #endif
+  }
+#endif
 #endif
 
   // generic, this still optimizes correctly on MSVC.
@@ -223,24 +231,24 @@ limb scalar_add(limb x, limb y, bool& overflow) noexcept {
 }
 
 // multiply two small integers, getting both the high and low bits.
-fastfloat_really_inline
-limb scalar_mul(limb x, limb y, limb& carry) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 limb
+scalar_mul(limb x, limb y, limb &carry) noexcept {
 #ifdef FASTFLOAT_64BIT_LIMB
-  #if defined(__SIZEOF_INT128__)
+#if defined(__SIZEOF_INT128__)
   // GCC and clang both define it as an extension.
   __uint128_t z = __uint128_t(x) * __uint128_t(y) + __uint128_t(carry);
   carry = limb(z >> limb_bits);
   return limb(z);
-  #else
+#else
   // fallback, no native 128-bit integer multiplication with carry.
   // on msvc, this optimizes identically, somehow.
   value128 z = full_multiplication(x, y);
   bool overflow;
   z.low = scalar_add(z.low, carry, overflow);
-  z.high += uint64_t(overflow);  // cannot overflow
+  z.high += uint64_t(overflow); // cannot overflow
   carry = z.high;
   return z.low;
-  #endif
+#endif
 #else
   uint64_t z = uint64_t(x) * uint64_t(y) + uint64_t(carry);
   carry = limb(z >> limb_bits);
@@ -251,7 +259,8 @@ limb scalar_mul(limb x, limb y, limb& carry) noexcept {
 // add scalar value to bigint starting from offset.
 // used in grade school multiplication
 template <uint16_t size>
-inline bool small_add_from(stackvec<size>& vec, limb y, size_t start) noexcept {
+inline FASTFLOAT_CONSTEXPR20 bool small_add_from(stackvec<size> &vec, limb y,
+                                                 size_t start) noexcept {
   size_t index = start;
   limb carry = y;
   bool overflow;
@@ -268,13 +277,15 @@ inline bool small_add_from(stackvec<size>& vec, limb y, size_t start) noexcept {
 
 // add scalar value to bigint.
 template <uint16_t size>
-fastfloat_really_inline bool small_add(stackvec<size>& vec, limb y) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 bool
+small_add(stackvec<size> &vec, limb y) noexcept {
   return small_add_from(vec, y, 0);
 }
 
 // multiply bigint by scalar value.
 template <uint16_t size>
-inline bool small_mul(stackvec<size>& vec, limb y) noexcept {
+inline FASTFLOAT_CONSTEXPR20 bool small_mul(stackvec<size> &vec,
+                                            limb y) noexcept {
   limb carry = 0;
   for (size_t index = 0; index < vec.len(); index++) {
     vec[index] = scalar_mul(vec[index], y, carry);
@@ -288,11 +299,12 @@ inline bool small_mul(stackvec<size>& vec, limb y) noexcept {
 // add bigint to bigint starting from index.
 // used in grade school multiplication
 template <uint16_t size>
-bool large_add_from(stackvec<size>& x, limb_span y, size_t start) noexcept {
+FASTFLOAT_CONSTEXPR20 bool large_add_from(stackvec<size> &x, limb_span y,
+                                          size_t start) noexcept {
   // the effective x buffer is from `xstart..x.len()`, so exit early
   // if we can't get that current range.
   if (x.len() < start || y.len() > x.len() - start) {
-      FASTFLOAT_TRY(x.try_resize(y.len() + start, 0));
+    FASTFLOAT_TRY(x.try_resize(y.len() + start, 0));
   }
 
   bool carry = false;
@@ -318,13 +330,14 @@ bool large_add_from(stackvec<size>& x, limb_span y, size_t start) noexcept {
 
 // add bigint to bigint.
 template <uint16_t size>
-fastfloat_really_inline bool large_add_from(stackvec<size>& x, limb_span y) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 bool
+large_add_from(stackvec<size> &x, limb_span y) noexcept {
   return large_add_from(x, y, 0);
 }
 
 // grade-school multiplication algorithm
 template <uint16_t size>
-bool long_mul(stackvec<size>& x, limb_span y) noexcept {
+FASTFLOAT_CONSTEXPR20 bool long_mul(stackvec<size> &x, limb_span y) noexcept {
   limb_span xs = limb_span(x.data, x.len());
   stackvec<size> z(xs);
   limb_span zs = limb_span(z.data, z.len());
@@ -352,7 +365,7 @@ bool long_mul(stackvec<size>& x, limb_span y) noexcept {
 
 // grade-school multiplication algorithm
 template <uint16_t size>
-bool large_mul(stackvec<size>& x, limb_span y) noexcept {
+FASTFLOAT_CONSTEXPR20 bool large_mul(stackvec<size> &x, limb_span y) noexcept {
   if (y.len() == 1) {
     FASTFLOAT_TRY(small_mul(x, y[0]));
   } else {
@@ -361,21 +374,75 @@ bool large_mul(stackvec<size>& x, limb_span y) noexcept {
   return true;
 }
 
+template <typename = void> struct pow5_tables {
+  static constexpr uint32_t large_step = 135;
+  static constexpr uint64_t small_power_of_5[] = {
+      1UL,
+      5UL,
+      25UL,
+      125UL,
+      625UL,
+      3125UL,
+      15625UL,
+      78125UL,
+      390625UL,
+      1953125UL,
+      9765625UL,
+      48828125UL,
+      244140625UL,
+      1220703125UL,
+      6103515625UL,
+      30517578125UL,
+      152587890625UL,
+      762939453125UL,
+      3814697265625UL,
+      19073486328125UL,
+      95367431640625UL,
+      476837158203125UL,
+      2384185791015625UL,
+      11920928955078125UL,
+      59604644775390625UL,
+      298023223876953125UL,
+      1490116119384765625UL,
+      7450580596923828125UL,
+  };
+#ifdef FASTFLOAT_64BIT_LIMB
+  constexpr static limb large_power_of_5[] = {
+      1414648277510068013UL, 9180637584431281687UL, 4539964771860779200UL,
+      10482974169319127550UL, 198276706040285095UL};
+#else
+  constexpr static limb large_power_of_5[] = {
+      4279965485U, 329373468U,  4020270615U, 2137533757U, 4287402176U,
+      1057042919U, 1071430142U, 2440757623U, 381945767U,  46164893U};
+#endif
+};
+
+#if FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE
+
+template <typename T> constexpr uint32_t pow5_tables<T>::large_step;
+
+template <typename T> constexpr uint64_t pow5_tables<T>::small_power_of_5[];
+
+template <typename T> constexpr limb pow5_tables<T>::large_power_of_5[];
+
+#endif
+
 // big integer type. implements a small subset of big integer
 // arithmetic, using simple algorithms since asymptotically
 // faster algorithms are slower for a small number of limbs.
 // all operations assume the big-integer is normalized.
-struct bigint {
+struct bigint : pow5_tables<> {
   // storage of the limbs, in little-endian order.
   stackvec<bigint_limbs> vec;
 
-  bigint(): vec() {}
-  bigint(const bigint &) = delete;
-  bigint &operator=(const bigint &) = delete;
+  FASTFLOAT_CONSTEXPR20 bigint() : vec() {}
+
+  bigint(bigint const &) = delete;
+  bigint &operator=(bigint const &) = delete;
   bigint(bigint &&) = delete;
   bigint &operator=(bigint &&other) = delete;
 
-  bigint(uint64_t value): vec() {
+  FASTFLOAT_CONSTEXPR20 bigint(uint64_t value) : vec() {
 #ifdef FASTFLOAT_64BIT_LIMB
     vec.push_unchecked(value);
 #else
@@ -387,7 +454,7 @@ struct bigint {
 
   // get the high 64 bits from the vector, and if bits were truncated.
   // this is to get the significant digits for the float.
-  uint64_t hi64(bool& truncated) const noexcept {
+  FASTFLOAT_CONSTEXPR20 uint64_t hi64(bool &truncated) const noexcept {
 #ifdef FASTFLOAT_64BIT_LIMB
     if (vec.len() == 0) {
       return empty_hi64(truncated);
@@ -406,7 +473,8 @@ struct bigint {
     } else if (vec.len() == 2) {
       return uint32_hi64(vec.rindex(0), vec.rindex(1), truncated);
     } else {
-      uint64_t result = uint32_hi64(vec.rindex(0), vec.rindex(1), vec.rindex(2), truncated);
+      uint64_t result =
+          uint32_hi64(vec.rindex(0), vec.rindex(1), vec.rindex(2), truncated);
       truncated |= vec.nonzero(3);
       return result;
     }
@@ -419,7 +487,7 @@ struct bigint {
   // positive, this is larger, otherwise they are equal.
   // the limbs are stored in little-endian order, so we
   // must compare the limbs in ever order.
-  int compare(const bigint& other) const noexcept {
+  FASTFLOAT_CONSTEXPR20 int compare(bigint const &other) const noexcept {
     if (vec.len() > other.vec.len()) {
       return 1;
     } else if (vec.len() < other.vec.len()) {
@@ -440,7 +508,7 @@ struct bigint {
 
   // shift left each limb n bits, carrying over to the new limb
   // returns true if we were able to shift all the digits.
-  bool shl_bits(size_t n) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool shl_bits(size_t n) noexcept {
     // Internally, for each item, we shift left by n, and add the previous
     // right shifted limb-bits.
     // For example, we transform (for u8) shifted left 2, to:
@@ -466,18 +534,18 @@ struct bigint {
   }
 
   // move the limbs left by `n` limbs.
-  bool shl_limbs(size_t n) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool shl_limbs(size_t n) noexcept {
     FASTFLOAT_DEBUG_ASSERT(n != 0);
     if (n + vec.len() > vec.capacity()) {
       return false;
     } else if (!vec.is_empty()) {
       // move limbs
-      limb* dst = vec.data + n;
-      const limb* src = vec.data;
-      ::memmove(dst, src, sizeof(limb) * vec.len());
+      limb *dst = vec.data + n;
+      limb const *src = vec.data;
+      std::copy_backward(src, src + vec.len(), dst + vec.len());
       // fill in empty limbs
-      limb* first = vec.data;
-      limb* last = first + n;
+      limb *first = vec.data;
+      limb *last = first + n;
       ::std::fill(first, last, 0);
       vec.set_len(n + vec.len());
       return true;
@@ -487,7 +555,7 @@ struct bigint {
   }
 
   // move the limbs left by `n` bits.
-  bool shl(size_t n) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool shl(size_t n) noexcept {
     size_t rem = n % limb_bits;
     size_t div = n / limb_bits;
     if (rem != 0) {
@@ -500,7 +568,7 @@ struct bigint {
   }
 
   // get the number of leading zeros in the bigint.
-  int ctlz() const noexcept {
+  FASTFLOAT_CONSTEXPR20 int ctlz() const noexcept {
     if (vec.is_empty()) {
       return 0;
     } else {
@@ -515,45 +583,21 @@ struct bigint {
   }
 
   // get the number of bits in the bigint.
-  int bit_length() const noexcept {
+  FASTFLOAT_CONSTEXPR20 int bit_length() const noexcept {
     int lz = ctlz();
     return int(limb_bits * vec.len()) - lz;
   }
 
-  bool mul(limb y) noexcept {
-    return small_mul(vec, y);
-  }
+  FASTFLOAT_CONSTEXPR20 bool mul(limb y) noexcept { return small_mul(vec, y); }
 
-  bool add(limb y) noexcept {
-    return small_add(vec, y);
-  }
+  FASTFLOAT_CONSTEXPR20 bool add(limb y) noexcept { return small_add(vec, y); }
 
   // multiply as if by 2 raised to a power.
-  bool pow2(uint32_t exp) noexcept {
-    return shl(exp);
-  }
+  FASTFLOAT_CONSTEXPR20 bool pow2(uint32_t exp) noexcept { return shl(exp); }
 
   // multiply as if by 5 raised to a power.
-  bool pow5(uint32_t exp) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool pow5(uint32_t exp) noexcept {
     // multiply by a power of 5
-    static constexpr uint32_t large_step = 135;
-    static constexpr uint64_t small_power_of_5[] = {
-      1UL, 5UL, 25UL, 125UL, 625UL, 3125UL, 15625UL, 78125UL, 390625UL,
-      1953125UL, 9765625UL, 48828125UL, 244140625UL, 1220703125UL,
-      6103515625UL, 30517578125UL, 152587890625UL, 762939453125UL,
-      3814697265625UL, 19073486328125UL, 95367431640625UL, 476837158203125UL,
-      2384185791015625UL, 11920928955078125UL, 59604644775390625UL,
-      298023223876953125UL, 1490116119384765625UL, 7450580596923828125UL,
-    };
-#ifdef FASTFLOAT_64BIT_LIMB
-    constexpr static limb large_power_of_5[] = {
-      1414648277510068013UL, 9180637584431281687UL, 4539964771860779200UL,
-      10482974169319127550UL, 198276706040285095UL};
-#else
-    constexpr static limb large_power_of_5[] = {
-      4279965485U, 329373468U, 4020270615U, 2137533757U, 4287402176U,
-      1057042919U, 1071430142U, 2440757623U, 381945767U, 46164893U};
-#endif
     size_t large_length = sizeof(large_power_of_5) / sizeof(limb);
     limb_span large = limb_span(large_power_of_5, large_length);
     while (exp >= large_step) {
@@ -572,14 +616,18 @@ struct bigint {
       exp -= small_step;
     }
     if (exp != 0) {
-      FASTFLOAT_TRY(small_mul(vec, limb(small_power_of_5[exp])));
+      // Work around clang bug https://godbolt.org/z/zedh7rrhc
+      // This is similar to https://github.com/llvm/llvm-project/issues/47746,
+      // except the workaround described there don't work here
+      FASTFLOAT_TRY(small_mul(
+          vec, limb(((void)small_power_of_5[0], small_power_of_5[exp]))));
     }
 
     return true;
   }
 
   // multiply as if by 10 raised to a power.
-  bool pow10(uint32_t exp) noexcept {
+  FASTFLOAT_CONSTEXPR20 bool pow10(uint32_t exp) noexcept {
     FASTFLOAT_TRY(pow5(exp));
     return pow2(exp);
   }

ThirdParty/fast_float/vtkfast_float/vtkfast_float/constexpr_feature_detect.h

+#ifndef FASTFLOAT_CONSTEXPR_FEATURE_DETECT_H
+#define FASTFLOAT_CONSTEXPR_FEATURE_DETECT_H
+
+#ifdef __has_include
+#if __has_include(<version>)
+#include <version>
+#endif
+#endif
+
+// Testing for https://wg21.link/N3652, adopted in C++14
+#if defined(__cpp_constexpr) && __cpp_constexpr >= 201304
+#define FASTFLOAT_CONSTEXPR14 constexpr
+#else
+#define FASTFLOAT_CONSTEXPR14
+#endif
+
+#if defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806L
+#define FASTFLOAT_HAS_BIT_CAST 1
+#else
+#define FASTFLOAT_HAS_BIT_CAST 0
+#endif
+
+#if defined(__cpp_lib_is_constant_evaluated) &&                                \
+    __cpp_lib_is_constant_evaluated >= 201811L
+#define FASTFLOAT_HAS_IS_CONSTANT_EVALUATED 1
+#else
+#define FASTFLOAT_HAS_IS_CONSTANT_EVALUATED 0
+#endif
+
+#if defined(__cpp_if_constexpr) && __cpp_if_constexpr >= 201606L
+#define FASTFLOAT_IF_CONSTEXPR17(x) if constexpr (x)
+#else
+#define FASTFLOAT_IF_CONSTEXPR17(x) if (x)
+#endif
+
+// Testing for relevant C++20 constexpr library features
+#if FASTFLOAT_HAS_IS_CONSTANT_EVALUATED && FASTFLOAT_HAS_BIT_CAST &&           \
+    defined(__cpp_lib_constexpr_algorithms) &&                                 \
+    __cpp_lib_constexpr_algorithms >= 201806L /*For std::copy and std::fill*/
+#define FASTFLOAT_CONSTEXPR20 constexpr
+#define FASTFLOAT_IS_CONSTEXPR 1
+#else
+#define FASTFLOAT_CONSTEXPR20
+#define FASTFLOAT_IS_CONSTEXPR 0
+#endif
+
+#if __cplusplus >= 201703L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
+#define FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE 0
+#else
+#define FASTFLOAT_DETAIL_MUST_DEFINE_CONSTEXPR_VARIABLE 1
+#endif
+
+#endif // FASTFLOAT_CONSTEXPR_FEATURE_DETECT_H

ThirdParty/fast_float/vtkfast_float/vtkfast_float/decimal_to_binary.h

@@ -12,27 +12,34 @@
 
 namespace fast_float {
 
-// This will compute or rather approximate w * 5**q and return a pair of 64-bit words approximating
-// the result, with the "high" part corresponding to the most significant bits and the
-// low part corresponding to the least significant bits.
+// This will compute or rather approximate w * 5**q and return a pair of 64-bit
+// words approximating the result, with the "high" part corresponding to the
+// most significant bits and the low part corresponding to the least significant
+// bits.
 //
 template <int bit_precision>
-fastfloat_really_inline
-value128 compute_product_approximation(int64_t q, uint64_t w) {
-  const int index = 2 * int(q - powers::smallest_power_of_five);
-  // For small values of q, e.g., q in [0,27], the answer is always exact because
-  // The line value128 firstproduct = full_multiplication(w, power_of_five_128[index]);
-  // gives the exact answer.
-  value128 firstproduct = full_multiplication(w, powers::power_of_five_128[index]);
-  static_assert((bit_precision >= 0) && (bit_precision <= 64), " precision should  be in (0,64]");
-  constexpr uint64_t precision_mask = (bit_precision < 64) ?
-               (uint64_t(0xFFFFFFFFFFFFFFFF) >> bit_precision)
-               : uint64_t(0xFFFFFFFFFFFFFFFF);
-  if((firstproduct.high & precision_mask) == precision_mask) { // could further guard with  (lower + w < lower)
-    // regarding the second product, we only need secondproduct.high, but our expectation is that the compiler will optimize this extra work away if needed.
-    value128 secondproduct = full_multiplication(w, powers::power_of_five_128[index + 1]);
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 value128
+compute_product_approximation(int64_t q, uint64_t w) {
+  int const index = 2 * int(q - powers::smallest_power_of_five);
+  // For small values of q, e.g., q in [0,27], the answer is always exact
+  // because The line value128 firstproduct = full_multiplication(w,
+  // power_of_five_128[index]); gives the exact answer.
+  value128 firstproduct =
+      full_multiplication(w, powers::power_of_five_128[index]);
+  static_assert((bit_precision >= 0) && (bit_precision <= 64),
+                " precision should  be in (0,64]");
+  constexpr uint64_t precision_mask =
+      (bit_precision < 64) ? (uint64_t(0xFFFFFFFFFFFFFFFF) >> bit_precision)
+                           : uint64_t(0xFFFFFFFFFFFFFFFF);
+  if ((firstproduct.high & precision_mask) ==
+      precision_mask) { // could further guard with  (lower + w < lower)
+    // regarding the second product, we only need secondproduct.high, but our
+    // expectation is that the compiler will optimize this extra work away if
+    // needed.
+    value128 secondproduct =
+        full_multiplication(w, powers::power_of_five_128[index + 1]);
     firstproduct.low += secondproduct.high;
-    if(secondproduct.high > firstproduct.low) {
+    if (secondproduct.high > firstproduct.low) {
       firstproduct.high++;
     }
   }
@@ -48,50 +55,52 @@ namespace detail {
  * where
  *   p = log(5**q)/log(2) = q * log(5)/log(2)
  *
- * For negative values of q in (-400,0), we have that 
+ * For negative values of q in (-400,0), we have that
  *  f = (((152170 + 65536) * q ) >> 16);
- * is equal to 
+ * is equal to
  *   -ceil(p) + q
  * where
  *   p = log(5**-q)/log(2) = -q * log(5)/log(2)
  */
-  constexpr fastfloat_really_inline int32_t power(int32_t q)  noexcept  {
-    return (((152170 + 65536) * q) >> 16) + 63;
-  }
+constexpr fastfloat_really_inline int32_t power(int32_t q) noexcept {
+  return (((152170 + 65536) * q) >> 16) + 63;
+}
 } // namespace detail
 
 // create an adjusted mantissa, biased by the invalid power2
 // for significant digits already multiplied by 10 ** q.
 template <typename binary>
-fastfloat_really_inline
-adjusted_mantissa compute_error_scaled(int64_t q, uint64_t w, int lz) noexcept  {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 adjusted_mantissa
+compute_error_scaled(int64_t q, uint64_t w, int lz) noexcept {
   int hilz = int(w >> 63) ^ 1;
   adjusted_mantissa answer;
   answer.mantissa = w << hilz;
   int bias = binary::mantissa_explicit_bits() - binary::minimum_exponent();
-  answer.power2 = int32_t(detail::power(int32_t(q)) + bias - hilz - lz - 62 + invalid_am_bias);
+  answer.power2 = int32_t(detail::power(int32_t(q)) + bias - hilz - lz - 62 +
+                          invalid_am_bias);
   return answer;
 }
 
 // w * 10 ** q, without rounding the representation up.
 // the power2 in the exponent will be adjusted by invalid_am_bias.
 template <typename binary>
-fastfloat_really_inline
-adjusted_mantissa compute_error(int64_t q, uint64_t w)  noexcept  {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa
+compute_error(int64_t q, uint64_t w) noexcept {
   int lz = leading_zeroes(w);
   w <<= lz;
-  value128 product = compute_product_approximation<binary::mantissa_explicit_bits() + 3>(q, w);
+  value128 product =
+      compute_product_approximation<binary::mantissa_explicit_bits() + 3>(q, w);
   return compute_error_scaled<binary>(q, product.high, lz);
 }
 
-// w * 10 ** q
-// The returned value should be a valid ieee64 number that simply need to be packed.
-// However, in some very rare cases, the computation will fail. In such cases, we
-// return an adjusted_mantissa with a negative power of 2: the caller should recompute
-// in such cases.
+// Computers w * 10 ** q.
+// The returned value should be a valid number that simply needs to be
+// packed. However, in some very rare cases, the computation will fail. In such
+// cases, we return an adjusted_mantissa with a negative power of 2: the caller
+// should recompute in such cases.
 template <typename binary>
-fastfloat_really_inline
-adjusted_mantissa compute_float(int64_t q, uint64_t w)  noexcept  {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa
+compute_float(int64_t q, uint64_t w) noexcept {
   adjusted_mantissa answer;
   if ((w == 0) || (q < binary::smallest_power_of_ten())) {
     answer.power2 = 0;
@@ -105,7 +114,8 @@ adjusted_mantissa compute_float(int64_t q, uint64_t w)  noexcept  {
     answer.mantissa = 0;
     return answer;
   }
-  // At this point in time q is in [powers::smallest_power_of_five, powers::largest_power_of_five].
+  // At this point in time q is in [powers::smallest_power_of_five,
+  // powers::largest_power_of_five].
 
   // We want the most significant bit of i to be 1. Shift if needed.
   int lz = leading_zeroes(w);
@@ -114,31 +124,32 @@ adjusted_mantissa compute_float(int64_t q, uint64_t w)  noexcept  {
   // The required precision is binary::mantissa_explicit_bits() + 3 because
   // 1. We need the implicit bit
   // 2. We need an extra bit for rounding purposes
-  // 3. We might lose a bit due to the "upperbit" routine (result too small, requiring a shift)
-
-  value128 product = compute_product_approximation<binary::mantissa_explicit_bits() + 3>(q, w);
-  if(product.low == 0xFFFFFFFFFFFFFFFF) { //  could guard it further
-    // In some very rare cases, this could happen, in which case we might need a more accurate
-    // computation that what we can provide cheaply. This is very, very unlikely.
-    //
-    const bool inside_safe_exponent = (q >= -27) && (q <= 55); // always good because 5**q <2**128 when q>=0, 
-    // and otherwise, for q<0, we have 5**-q<2**64 and the 128-bit reciprocal allows for exact computation.
-    if(!inside_safe_exponent) {
-      return compute_error_scaled<binary>(q, product.high, lz);
-    }
-  }
-  // The "compute_product_approximation" function can be slightly slower than a branchless approach:
-  // value128 product = compute_product(q, w);
-  // but in practice, we can win big with the compute_product_approximation if its additional branch
-  // is easily predicted. Which is best is data specific.
+  // 3. We might lose a bit due to the "upperbit" routine (result too small,
+  // requiring a shift)
+
+  value128 product =
+      compute_product_approximation<binary::mantissa_explicit_bits() + 3>(q, w);
+  // The computed 'product' is always sufficient.
+  // Mathematical proof:
+  // Noble Mushtak and Daniel Lemire, Fast Number Parsing Without Fallback (to
+  // appear) See script/mushtak_lemire.py
+
+  // The "compute_product_approximation" function can be slightly slower than a
+  // branchless approach: value128 product = compute_product(q, w); but in
+  // practice, we can win big with the compute_product_approximation if its
+  // additional branch is easily predicted. Which is best is data specific.
   int upperbit = int(product.high >> 63);
+  int shift = upperbit + 64 - binary::mantissa_explicit_bits() - 3;
 
-  answer.mantissa = product.high >> (upperbit + 64 - binary::mantissa_explicit_bits() - 3);
+  answer.mantissa = product.high >> shift;
 
-  answer.power2 = int32_t(detail::power(int32_t(q)) + upperbit - lz - binary::minimum_exponent());
+  answer.power2 = int32_t(detail::power(int32_t(q)) + upperbit - lz -
+                          binary::minimum_exponent());
   if (answer.power2 <= 0) { // we have a subnormal?
     // Here have that answer.power2 <= 0 so -answer.power2 >= 0
-    if(-answer.power2 + 1 >= 64) { // if we have more than 64 bits below the minimum exponent, you have a zero for sure.
+    if (-answer.power2 + 1 >=
+        64) { // if we have more than 64 bits below the minimum exponent, you
+              // have a zero for sure.
       answer.power2 = 0;
       answer.mantissa = 0;
       // result should be zero
@@ -147,7 +158,8 @@ adjusted_mantissa compute_float(int64_t q, uint64_t w)  noexcept  {
     // next line is safe because -answer.power2 + 1 < 64
     answer.mantissa >>= -answer.power2 + 1;
     // Thankfully, we can't have both "round-to-even" and subnormals because
-    // "round-to-even" only occurs for powers close to 0.
+    // "round-to-even" only occurs for powers close to 0 in the 32-bit and
+    // and 64-bit case (with no more than 19 digits).
     answer.mantissa += (answer.mantissa & 1); // round up
     answer.mantissa >>= 1;
     // There is a weird scenario where we don't have a subnormal but just.
@@ -157,20 +169,26 @@ adjusted_mantissa compute_float(int64_t q, uint64_t w)  noexcept  {
     // up 0x3fffffffffffff x 2^-1023-53  and once we do, we are no longer
     // subnormal, but we can only know this after rounding.
     // So we only declare a subnormal if we are smaller than the threshold.
-    answer.power2 = (answer.mantissa < (uint64_t(1) << binary::mantissa_explicit_bits())) ? 0 : 1;
+    answer.power2 =
+        (answer.mantissa < (uint64_t(1) << binary::mantissa_explicit_bits()))
+            ? 0
+            : 1;
     return answer;
   }
 
   // usually, we round *up*, but if we fall right in between and and we have an
   // even basis, we need to round down
   // We are only concerned with the cases where 5**q fits in single 64-bit word.
-  if ((product.low <= 1) &&  (q >= binary::min_exponent_round_to_even()) && (q <= binary::max_exponent_round_to_even()) &&
-      ((answer.mantissa & 3) == 1) ) { // we may fall between two floats!
+  if ((product.low <= 1) && (q >= binary::min_exponent_round_to_even()) &&
+      (q <= binary::max_exponent_round_to_even()) &&
+      ((answer.mantissa & 3) == 1)) { // we may fall between two floats!
     // To be in-between two floats we need that in doing
-    //   answer.mantissa = product.high >> (upperbit + 64 - binary::mantissa_explicit_bits() - 3);
-    // ... we dropped out only zeroes. But if this happened, then we can go back!!!
-    if((answer.mantissa  << (upperbit + 64 - binary::mantissa_explicit_bits() - 3)) ==  product.high) {
-      answer.mantissa &= ~uint64_t(1);          // flip it so that we do not round up
+    //   answer.mantissa = product.high >> (upperbit + 64 -
+    //   binary::mantissa_explicit_bits() - 3);
+    // ... we dropped out only zeroes. But if this happened, then we can go
+    // back!!!
+    if ((answer.mantissa << shift) == product.high) {
+      answer.mantissa &= ~uint64_t(1); // flip it so that we do not round up
     }
   }
 

ThirdParty/fast_float/vtkfast_float/vtkfast_float/digit_comparison.h

@@ -13,17 +13,34 @@
 namespace fast_float {
 
 // 1e0 to 1e19
-constexpr static uint64_t powers_of_ten_uint64[] = {
-    1UL, 10UL, 100UL, 1000UL, 10000UL, 100000UL, 1000000UL, 10000000UL, 100000000UL,
-    1000000000UL, 10000000000UL, 100000000000UL, 1000000000000UL, 10000000000000UL,
-    100000000000000UL, 1000000000000000UL, 10000000000000000UL, 100000000000000000UL,
-    1000000000000000000UL, 10000000000000000000UL};
+constexpr static uint64_t powers_of_ten_uint64[] = {1UL,
+                                                    10UL,
+                                                    100UL,
+                                                    1000UL,
+                                                    10000UL,
+                                                    100000UL,
+                                                    1000000UL,
+                                                    10000000UL,
+                                                    100000000UL,
+                                                    1000000000UL,
+                                                    10000000000UL,
+                                                    100000000000UL,
+                                                    1000000000000UL,
+                                                    10000000000000UL,
+                                                    100000000000000UL,
+                                                    1000000000000000UL,
+                                                    10000000000000000UL,
+                                                    100000000000000000UL,
+                                                    1000000000000000000UL,
+                                                    10000000000000000000UL};
 
 // calculate the exponent, in scientific notation, of the number.
 // this algorithm is not even close to optimized, but it has no practical
 // effect on performance: in order to have a faster algorithm, we'd need
 // to slow down performance for faster algorithms, and this is still fast.
-fastfloat_really_inline int32_t scientific_exponent(parsed_number_string& num) noexcept {
+template <typename UC>
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 int32_t
+scientific_exponent(parsed_number_string_t<UC> &num) noexcept {
   uint64_t mantissa = num.mantissa;
   int32_t exponent = int32_t(num.exponent);
   while (mantissa >= 10000) {
@@ -43,23 +60,30 @@ fastfloat_really_inline int32_t scientific_exponent(parsed_number_string& num) n
 
 // this converts a native floating-point number to an extended-precision float.
 template <typename T>
-fastfloat_really_inline adjusted_mantissa to_extended(T value) noexcept {
-  using equiv_uint = typename binary_format<T>::equiv_uint;
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa
+to_extended(T value) noexcept {
+  using equiv_uint = equiv_uint_t<T>;
   constexpr equiv_uint exponent_mask = binary_format<T>::exponent_mask();
   constexpr equiv_uint mantissa_mask = binary_format<T>::mantissa_mask();
   constexpr equiv_uint hidden_bit_mask = binary_format<T>::hidden_bit_mask();
 
   adjusted_mantissa am;
-  int32_t bias = binary_format<T>::mantissa_explicit_bits() - binary_format<T>::minimum_exponent();
+  int32_t bias = binary_format<T>::mantissa_explicit_bits() -
+                 binary_format<T>::minimum_exponent();
   equiv_uint bits;
+#if FASTFLOAT_HAS_BIT_CAST
+  bits = std::bit_cast<equiv_uint>(value);
+#else
   ::memcpy(&bits, &value, sizeof(T));
+#endif
   if ((bits & exponent_mask) == 0) {
     // denormal
     am.power2 = 1 - bias;
     am.mantissa = bits & mantissa_mask;
   } else {
     // normal
-    am.power2 = int32_t((bits & exponent_mask) >> binary_format<T>::mantissa_explicit_bits());
+    am.power2 = int32_t((bits & exponent_mask) >>
+                        binary_format<T>::mantissa_explicit_bits());
     am.power2 -= bias;
     am.mantissa = (bits & mantissa_mask) | hidden_bit_mask;
   }
@@ -71,7 +95,8 @@ fastfloat_really_inline adjusted_mantissa to_extended(T value) noexcept {
 // we are given a native float that represents b, so we need to adjust it
 // halfway between b and b+u.
 template <typename T>
-fastfloat_really_inline adjusted_mantissa to_extended_halfway(T value) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa
+to_extended_halfway(T value) noexcept {
   adjusted_mantissa am = to_extended(value);
   am.mantissa <<= 1;
   am.mantissa += 1;
@@ -81,14 +106,18 @@ fastfloat_really_inline adjusted_mantissa to_extended_halfway(T value) noexcept
 
 // round an extended-precision float to the nearest machine float.
 template <typename T, typename callback>
-fastfloat_really_inline void round(adjusted_mantissa& am, callback cb) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 void round(adjusted_mantissa &am,
+                                                         callback cb) noexcept {
   int32_t mantissa_shift = 64 - binary_format<T>::mantissa_explicit_bits() - 1;
   if (-am.power2 >= mantissa_shift) {
     // have a denormal float
     int32_t shift = -am.power2 + 1;
     cb(am, std::min<int32_t>(shift, 64));
     // check for round-up: if rounding-nearest carried us to the hidden bit.
-    am.power2 = (am.mantissa < (uint64_t(1) << binary_format<T>::mantissa_explicit_bits())) ? 0 : 1;
+    am.power2 = (am.mantissa <
+                 (uint64_t(1) << binary_format<T>::mantissa_explicit_bits()))
+                    ? 0
+                    : 1;
     return;
   }
 
@@ -96,7 +125,8 @@ fastfloat_really_inline void round(adjusted_mantissa& am, callback cb) noexcept
   cb(am, mantissa_shift);
 
   // check for carry
-  if (am.mantissa >= (uint64_t(2) << binary_format<T>::mantissa_explicit_bits())) {
+  if (am.mantissa >=
+      (uint64_t(2) << binary_format<T>::mantissa_explicit_bits())) {
     am.mantissa = (uint64_t(1) << binary_format<T>::mantissa_explicit_bits());
     am.power2++;
   }
@@ -110,20 +140,11 @@ fastfloat_really_inline void round(adjusted_mantissa& am, callback cb) noexcept
 }
 
 template <typename callback>
-fastfloat_really_inline
-void round_nearest_tie_even(adjusted_mantissa& am, int32_t shift, callback cb) noexcept {
-  uint64_t mask;
-  uint64_t halfway;
-  if (shift == 64) {
-    mask = UINT64_MAX;
-  } else {
-    mask = (uint64_t(1) << shift) - 1;
-  }
-  if (shift == 0) {
-    halfway = 0;
-  } else {
-    halfway = uint64_t(1) << (shift - 1);
-  }
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 void
+round_nearest_tie_even(adjusted_mantissa &am, int32_t shift,
+                       callback cb) noexcept {
+  uint64_t const mask = (shift == 64) ? UINT64_MAX : (uint64_t(1) << shift) - 1;
+  uint64_t const halfway = (shift == 0) ? 0 : uint64_t(1) << (shift - 1);
   uint64_t truncated_bits = am.mantissa & mask;
   bool is_above = truncated_bits > halfway;
   bool is_halfway = truncated_bits == halfway;
@@ -140,7 +161,8 @@ void round_nearest_tie_even(adjusted_mantissa& am, int32_t shift, callback cb) n
   am.mantissa += uint64_t(cb(is_odd, is_halfway, is_above));
 }
 
-fastfloat_really_inline void round_down(adjusted_mantissa& am, int32_t shift) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 void
+round_down(adjusted_mantissa &am, int32_t shift) noexcept {
   if (shift == 64) {
     am.mantissa = 0;
   } else {
@@ -149,17 +171,20 @@ fastfloat_really_inline void round_down(adjusted_mantissa& am, int32_t shift) no
   am.power2 += shift;
 }
 
-fastfloat_really_inline void skip_zeros(const char*& first, const char* last) noexcept {
+template <typename UC>
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 void
+skip_zeros(UC const *&first, UC const *last) noexcept {
   uint64_t val;
-  while (std::distance(first, last) >= 8) {
+  while (!cpp20_and_in_constexpr() &&
+         std::distance(first, last) >= int_cmp_len<UC>()) {
     ::memcpy(&val, first, sizeof(uint64_t));
-    if (val != 0x3030303030303030) {
+    if (val != int_cmp_zeros<UC>()) {
       break;
     }
-    first += 8;
+    first += int_cmp_len<UC>();
   }
   while (first != last) {
-    if (*first != '0') {
+    if (*first != UC('0')) {
       break;
     }
     first++;
@@ -168,52 +193,62 @@ fastfloat_really_inline void skip_zeros(const char*& first, const char* last) no
 
 // determine if any non-zero digits were truncated.
 // all characters must be valid digits.
-fastfloat_really_inline bool is_truncated(const char* first, const char* last) noexcept {
+template <typename UC>
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 bool
+is_truncated(UC const *first, UC const *last) noexcept {
   // do 8-bit optimizations, can just compare to 8 literal 0s.
   uint64_t val;
-  while (std::distance(first, last) >= 8) {
+  while (!cpp20_and_in_constexpr() &&
+         std::distance(first, last) >= int_cmp_len<UC>()) {
     ::memcpy(&val, first, sizeof(uint64_t));
-    if (val != 0x3030303030303030) {
+    if (val != int_cmp_zeros<UC>()) {
       return true;
     }
-    first += 8;
+    first += int_cmp_len<UC>();
   }
   while (first != last) {
-    if (*first != '0') {
+    if (*first != UC('0')) {
       return true;
     }
-    first++;
+    ++first;
   }
   return false;
 }
 
-fastfloat_really_inline bool is_truncated(byte_span s) noexcept {
+template <typename UC>
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 bool
+is_truncated(span<UC const> s) noexcept {
   return is_truncated(s.ptr, s.ptr + s.len());
 }
 
-fastfloat_really_inline
-void parse_eight_digits(const char*& p, limb& value, size_t& counter, size_t& count) noexcept {
+template <typename UC>
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 void
+parse_eight_digits(UC const *&p, limb &value, size_t &counter,
+                   size_t &count) noexcept {
   value = value * 100000000 + parse_eight_digits_unrolled(p);
   p += 8;
   counter += 8;
   count += 8;
 }
 
-fastfloat_really_inline
-void parse_one_digit(const char*& p, limb& value, size_t& counter, size_t& count) noexcept {
-  value = value * 10 + limb(*p - '0');
+template <typename UC>
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14 void
+parse_one_digit(UC const *&p, limb &value, size_t &counter,
+                size_t &count) noexcept {
+  value = value * 10 + limb(*p - UC('0'));
   p++;
   counter++;
   count++;
 }
 
-fastfloat_really_inline
-void add_native(bigint& big, limb power, limb value) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 void
+add_native(bigint &big, limb power, limb value) noexcept {
   big.mul(power);
   big.add(value);
 }
 
-fastfloat_really_inline void round_up_bigint(bigint& big, size_t& count) noexcept {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 void
+round_up_bigint(bigint &big, size_t &count) noexcept {
   // need to round-up the digits, but need to avoid rounding
   // ....9999 to ...10000, which could cause a false halfway point.
   add_native(big, 10, 1);
@@ -221,7 +256,10 @@ fastfloat_really_inline void round_up_bigint(bigint& big, size_t& count) noexcep
 }
 
 // parse the significant digits into a big integer
-inline void parse_mantissa(bigint& result, parsed_number_string& num, size_t max_digits, size_t& digits) noexcept {
+template <typename UC>
+inline FASTFLOAT_CONSTEXPR20 void
+parse_mantissa(bigint &result, parsed_number_string_t<UC> &num,
+               size_t max_digits, size_t &digits) noexcept {
   // try to minimize the number of big integer and scalar multiplication.
   // therefore, try to parse 8 digits at a time, and multiply by the largest
   // scalar value (9 or 19 digits) for each step.
@@ -235,12 +273,13 @@ inline void parse_mantissa(bigint& result, parsed_number_string& num, size_t max
 #endif
 
   // process all integer digits.
-  const char* p = num.integer.ptr;
-  const char* pend = p + num.integer.len();
+  UC const *p = num.integer.ptr;
+  UC const *pend = p + num.integer.len();
   skip_zeros(p, pend);
   // process all digits, in increments of step per loop
   while (p != pend) {
-    while ((std::distance(p, pend) >= 8) && (step - counter >= 8) && (max_digits - digits >= 8)) {
+    while ((std::distance(p, pend) >= 8) && (step - counter >= 8) &&
+           (max_digits - digits >= 8)) {
       parse_eight_digits(p, value, counter, digits);
     }
     while (counter < step && p != pend && digits < max_digits) {
@@ -273,7 +312,8 @@ inline void parse_mantissa(bigint& result, parsed_number_string& num, size_t max
     }
     // process all digits, in increments of step per loop
     while (p != pend) {
-      while ((std::distance(p, pend) >= 8) && (step - counter >= 8) && (max_digits - digits >= 8)) {
+      while ((std::distance(p, pend) >= 8) && (step - counter >= 8) &&
+             (max_digits - digits >= 8)) {
         parse_eight_digits(p, value, counter, digits);
       }
       while (counter < step && p != pend && digits < max_digits) {
@@ -301,18 +341,23 @@ inline void parse_mantissa(bigint& result, parsed_number_string& num, size_t max
 }
 
 template <typename T>
-inline adjusted_mantissa positive_digit_comp(bigint& bigmant, int32_t exponent) noexcept {
+inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa
+positive_digit_comp(bigint &bigmant, int32_t exponent) noexcept {
   FASTFLOAT_ASSERT(bigmant.pow10(uint32_t(exponent)));
   adjusted_mantissa answer;
   bool truncated;
   answer.mantissa = bigmant.hi64(truncated);
-  int bias = binary_format<T>::mantissa_explicit_bits() - binary_format<T>::minimum_exponent();
+  int bias = binary_format<T>::mantissa_explicit_bits() -
+             binary_format<T>::minimum_exponent();
   answer.power2 = bigmant.bit_length() - 64 + bias;
 
-  round<T>(answer, [truncated](adjusted_mantissa& a, int32_t shift) {
-    round_nearest_tie_even(a, shift, [truncated](bool is_odd, bool is_halfway, bool is_above) -> bool {
-      return is_above || (is_halfway && truncated) || (is_odd && is_halfway);
-    });
+  round<T>(answer, [truncated](adjusted_mantissa &a, int32_t shift) {
+    round_nearest_tie_even(
+        a, shift,
+        [truncated](bool is_odd, bool is_halfway, bool is_above) -> bool {
+          return is_above || (is_halfway && truncated) ||
+                 (is_odd && is_halfway);
+        });
   });
 
   return answer;
@@ -324,14 +369,17 @@ inline adjusted_mantissa positive_digit_comp(bigint& bigmant, int32_t exponent)
 // we then need to scale by `2^(f- e)`, and then the two significant digits
 // are of the same magnitude.
 template <typename T>
-inline adjusted_mantissa negative_digit_comp(bigint& bigmant, adjusted_mantissa am, int32_t exponent) noexcept {
-  bigint& real_digits = bigmant;
+inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa negative_digit_comp(
+    bigint &bigmant, adjusted_mantissa am, int32_t exponent) noexcept {
+  bigint &real_digits = bigmant;
   int32_t real_exp = exponent;
 
   // get the value of `b`, rounded down, and get a bigint representation of b+h
   adjusted_mantissa am_b = am;
-  // gcc7 buf: use a lambda to remove the noexcept qualifier bug with -Wnoexcept-type.
-  round<T>(am_b, [](adjusted_mantissa&a, int32_t shift) { round_down(a, shift); });
+  // gcc7 buf: use a lambda to remove the noexcept qualifier bug with
+  // -Wnoexcept-type.
+  round<T>(am_b,
+           [](adjusted_mantissa &a, int32_t shift) { round_down(a, shift); });
   T b;
   to_float(false, am_b, b);
   adjusted_mantissa theor = to_extended_halfway(b);
@@ -353,18 +401,19 @@ inline adjusted_mantissa negative_digit_comp(bigint& bigmant, adjusted_mantissa
   // compare digits, and use it to director rounding
   int ord = real_digits.compare(theor_digits);
   adjusted_mantissa answer = am;
-  round<T>(answer, [ord](adjusted_mantissa& a, int32_t shift) {
-    round_nearest_tie_even(a, shift, [ord](bool is_odd, bool _, bool __) -> bool {
-      (void)_;  // not needed, since we've done our comparison
-      (void)__; // not needed, since we've done our comparison
-      if (ord > 0) {
-        return true;
-      } else if (ord < 0) {
-        return false;
-      } else {
-        return is_odd;
-      }
-    });
+  round<T>(answer, [ord](adjusted_mantissa &a, int32_t shift) {
+    round_nearest_tie_even(
+        a, shift, [ord](bool is_odd, bool _, bool __) -> bool {
+          (void)_;  // not needed, since we've done our comparison
+          (void)__; // not needed, since we've done our comparison
+          if (ord > 0) {
+            return true;
+          } else if (ord < 0) {
+            return false;
+          } else {
+            return is_odd;
+          }
+        });
   });
 
   return answer;
@@ -383,8 +432,9 @@ inline adjusted_mantissa negative_digit_comp(bigint& bigmant, adjusted_mantissa
 // `b` as a big-integer type, scaled to the same binary exponent as
 // the actual digits. we then compare the big integer representations
 // of both, and use that to direct rounding.
-template <typename T>
-inline adjusted_mantissa digit_comp(parsed_number_string& num, adjusted_mantissa am) noexcept {
+template <typename T, typename UC>
+inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa
+digit_comp(parsed_number_string_t<UC> &num, adjusted_mantissa am) noexcept {
   // remove the invalid exponent bias
   am.power2 -= invalid_am_bias;
 

ThirdParty/fast_float/vtkfast_float/vtkfast_float/fast_float.h

+
 #ifndef FASTFLOAT_FAST_FLOAT_H
 #define FASTFLOAT_FAST_FLOAT_H
 
-#include "vtkfast_float_mangle.h"
-
-#include <system_error>
+#include "float_common.h"
 
 namespace fast_float {
-enum chars_format {
-    scientific = 1<<0,
-    fixed = 1<<2,
-    hex = 1<<3,
-    general = fixed | scientific
-};
-
-
-struct from_chars_result {
-  const char *ptr;
-  std::errc ec;
-};
-
-struct parse_options {
-  constexpr explicit parse_options(chars_format fmt = chars_format::general,
-                         char dot = '.')
-    : format(fmt), decimal_point(dot) {}
-
-  /** Which number formats are accepted */
-  chars_format format;
-  /** The character used as decimal point */
-  char decimal_point;
-};
-
 /**
- * This function parses the character sequence [first,last) for a number. It parses floating-point numbers expecting
- * a locale-indepent format equivalent to what is used by std::strtod in the default ("C") locale.
- * The resulting floating-point value is the closest floating-point values (using either float or double),
- * using the "round to even" convention for values that would otherwise fall right in-between two values.
- * That is, we provide exact parsing according to the IEEE standard.
+ * This function parses the character sequence [first,last) for a number. It
+ * parses floating-point numbers expecting a locale-indepent format equivalent
+ * to what is used by std::strtod in the default ("C") locale. The resulting
+ * floating-point value is the closest floating-point values (using either float
+ * or double), using the "round to even" convention for values that would
+ * otherwise fall right in-between two values. That is, we provide exact parsing
+ * according to the IEEE standard.
  *
- * Given a successful parse, the pointer (`ptr`) in the returned value is set to point right after the
- * parsed number, and the `value` referenced is set to the parsed value. In case of error, the returned
- * `ec` contains a representative error, otherwise the default (`std::errc()`) value is stored.
+ * Given a successful parse, the pointer (`ptr`) in the returned value is set to
+ * point right after the parsed number, and the `value` referenced is set to the
+ * parsed value. In case of error, the returned `ec` contains a representative
+ * error, otherwise the default (`std::errc()`) value is stored.
  *
- * The implementation does not throw and does not allocate memory (e.g., with `new` or `malloc`).
+ * The implementation does not throw and does not allocate memory (e.g., with
+ * `new` or `malloc`).
  *
- * Like the C++17 standard, the `fast_float::from_chars` functions take an optional last argument of
- * the type `fast_float::chars_format`. It is a bitset value: we check whether
- * `fmt & fast_float::chars_format::fixed` and `fmt & fast_float::chars_format::scientific` are set
- * to determine whether we allow the fixed point and scientific notation respectively.
- * The default is  `fast_float::chars_format::general` which allows both `fixed` and `scientific`.
+ * Like the C++17 standard, the `fast_float::from_chars` functions take an
+ * optional last argument of the type `fast_float::chars_format`. It is a bitset
+ * value: we check whether `fmt & fast_float::chars_format::fixed` and `fmt &
+ * fast_float::chars_format::scientific` are set to determine whether we allow
+ * the fixed point and scientific notation respectively. The default is
+ * `fast_float::chars_format::general` which allows both `fixed` and
+ * `scientific`.
  */
-template<typename T>
-from_chars_result from_chars(const char *first, const char *last,
-                             T &value, chars_format fmt = chars_format::general)  noexcept;
+template <typename T, typename UC = char,
+          typename = FASTFLOAT_ENABLE_IF(is_supported_float_type<T>::value)>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars(UC const *first, UC const *last, T &value,
+           chars_format fmt = chars_format::general) noexcept;
 
 /**
  * Like from_chars, but accepts an `options` argument to govern number parsing.
+ * Both for floating-point types and integer types.
  */
-template<typename T>
-from_chars_result from_chars_advanced(const char *first, const char *last,
-                                      T &value, parse_options options)  noexcept;
+template <typename T, typename UC = char>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars_advanced(UC const *first, UC const *last, T &value,
+                    parse_options_t<UC> options) noexcept;
+
+/**
+ * from_chars for integer types.
+ */
+template <typename T, typename UC = char,
+          typename = FASTFLOAT_ENABLE_IF(is_supported_integer_type<T>::value)>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars(UC const *first, UC const *last, T &value, int base = 10) noexcept;
 
 } // namespace fast_float
+
 #include "parse_number.h"
 #endif // FASTFLOAT_FAST_FLOAT_H

ThirdParty/fast_float/vtkfast_float/vtkfast_float/parse_number.h

@@ -4,6 +4,7 @@
 #include "ascii_number.h"
 #include "decimal_to_binary.h"
 #include "digit_comparison.h"
+#include "float_common.h"
 
 #include <cmath>
 #include <cstring>
@@ -12,47 +13,56 @@
 
 namespace fast_float {
 
-
 namespace detail {
 /**
  * Special case +inf, -inf, nan, infinity, -infinity.
  * The case comparisons could be made much faster given that we know that the
  * strings a null-free and fixed.
  **/
-template <typename T>
-from_chars_result parse_infnan(const char *first, const char *last, T &value)  noexcept  {
-  from_chars_result answer;
+template <typename T, typename UC>
+from_chars_result_t<UC>
+    FASTFLOAT_CONSTEXPR14 parse_infnan(UC const *first, UC const *last,
+                                       T &value, chars_format fmt) noexcept {
+  from_chars_result_t<UC> answer{};
   answer.ptr = first;
   answer.ec = std::errc(); // be optimistic
-  bool minusSign = false;
-  if (*first == '-') { // assume first < last, so dereference without checks; C++17 20.19.3.(7.1) explicitly forbids '+' here
-      minusSign = true;
-      ++first;
+  // assume first < last, so dereference without checks;
+  bool const minusSign = (*first == UC('-'));
+  // C++17 20.19.3.(7.1) explicitly forbids '+' sign here
+  if ((*first == UC('-')) ||
+      (uint64_t(fmt & chars_format::allow_leading_plus) &&
+       (*first == UC('+')))) {
+    ++first;
   }
   if (last - first >= 3) {
-    if (fastfloat_strncasecmp(first, "nan", 3)) {
+    if (fastfloat_strncasecmp(first, str_const_nan<UC>(), 3)) {
       answer.ptr = (first += 3);
-      value = minusSign ? -std::numeric_limits<T>::quiet_NaN() : std::numeric_limits<T>::quiet_NaN();
-      // Check for possible nan(n-char-seq-opt), C++17 20.19.3.7, C11 7.20.1.3.3. At least MSVC produces nan(ind) and nan(snan).
-      if(first != last && *first == '(') {
-        for(const char* ptr = first + 1; ptr != last; ++ptr) {
-          if (*ptr == ')') {
+      value = minusSign ? -std::numeric_limits<T>::quiet_NaN()
+                        : std::numeric_limits<T>::quiet_NaN();
+      // Check for possible nan(n-char-seq-opt), C++17 20.19.3.7,
+      // C11 7.20.1.3.3. At least MSVC produces nan(ind) and nan(snan).
+      if (first != last && *first == UC('(')) {
+        for (UC const *ptr = first + 1; ptr != last; ++ptr) {
+          if (*ptr == UC(')')) {
             answer.ptr = ptr + 1; // valid nan(n-char-seq-opt)
             break;
-          }
-          else if(!(('a' <= *ptr && *ptr <= 'z') || ('A' <= *ptr && *ptr <= 'Z') || ('0' <= *ptr && *ptr <= '9') || *ptr == '_'))
+          } else if (!((UC('a') <= *ptr && *ptr <= UC('z')) ||
+                       (UC('A') <= *ptr && *ptr <= UC('Z')) ||
+                       (UC('0') <= *ptr && *ptr <= UC('9')) || *ptr == UC('_')))
             break; // forbidden char, not nan(n-char-seq-opt)
         }
       }
       return answer;
     }
-    if (fastfloat_strncasecmp(first, "inf", 3)) {
-      if ((last - first >= 8) && fastfloat_strncasecmp(first + 3, "inity", 5)) {
+    if (fastfloat_strncasecmp(first, str_const_inf<UC>(), 3)) {
+      if ((last - first >= 8) &&
+          fastfloat_strncasecmp(first + 3, str_const_inf<UC>() + 3, 5)) {
         answer.ptr = first + 8;
       } else {
         answer.ptr = first + 3;
       }
-      value = minusSign ? -std::numeric_limits<T>::infinity() : std::numeric_limits<T>::infinity();
+      value = minusSign ? -std::numeric_limits<T>::infinity()
+                        : std::numeric_limits<T>::infinity();
       return answer;
     }
   }
@@ -66,6 +76,10 @@ from_chars_result parse_infnan(const char *first, const char *last, T &value)  n
  * Credit : @mwalcott3
  */
 fastfloat_really_inline bool rounds_to_nearest() noexcept {
+  // https://lemire.me/blog/2020/06/26/gcc-not-nearest/
+#if (FLT_EVAL_METHOD != 1) && (FLT_EVAL_METHOD != 0)
+  return false;
+#endif
   // See
   // A fast function to check your floating-point rounding mode
   // https://lemire.me/blog/2022/11/16/a-fast-function-to-check-your-floating-point-rounding-mode/
@@ -76,88 +90,130 @@ fastfloat_really_inline bool rounds_to_nearest() noexcept {
   // However, it is expected to be much faster than the fegetround()
   // function call.
   //
-  // The volatile keywoard prevents the compiler from computing the function
+  // The volatile keyword prevents the compiler from computing the function
   // at compile-time.
-  // There might be other ways to prevent compile-time optimizations (e.g., asm).
-  // The value does not need to be std::numeric_limits<float>::min(), any small
-  // value so that 1 + x should round to 1 would do (after accounting for excess
-  // precision, as in 387 instructions).
-  static volatile float fmin = std::numeric_limits<float>::min();
+  // There might be other ways to prevent compile-time optimizations (e.g.,
+  // asm). The value does not need to be std::numeric_limits<float>::min(), any
+  // small value so that 1 + x should round to 1 would do (after accounting for
+  // excess precision, as in 387 instructions).
+  static float volatile fmin = std::numeric_limits<float>::min();
   float fmini = fmin; // we copy it so that it gets loaded at most once.
-  //
-  // Explanation:
-  // Only when fegetround() == FE_TONEAREST do we have that
-  // fmin + 1.0f == 1.0f - fmin.
-  //
-  // FE_UPWARD:
-  //  fmin + 1.0f > 1
-  //  1.0f - fmin == 1
-  //
-  // FE_DOWNWARD or  FE_TOWARDZERO:
-  //  fmin + 1.0f == 1
-  //  1.0f - fmin < 1
-  //
-  // Note: This may fail to be accurate if fast-math has been
-  // enabled, as rounding conventions may not apply.
-  #if FASTFLOAT_VISUAL_STUDIO
-  #   pragma warning(push)
-  //  todo: is there a VS warning?
-  //  see https://stackoverflow.com/questions/46079446/is-there-a-warning-for-floating-point-equality-checking-in-visual-studio-2013
-  #elif defined(__clang__)
-  #   pragma clang diagnostic push
-  #   pragma clang diagnostic ignored "-Wfloat-equal"
-  #elif defined(__GNUC__)
-  #   pragma GCC diagnostic push
-  #   pragma GCC diagnostic ignored "-Wfloat-equal"
-  #endif
+//
+// Explanation:
+// Only when fegetround() == FE_TONEAREST do we have that
+// fmin + 1.0f == 1.0f - fmin.
+//
+// FE_UPWARD:
+//  fmin + 1.0f > 1
+//  1.0f - fmin == 1
+//
+// FE_DOWNWARD or  FE_TOWARDZERO:
+//  fmin + 1.0f == 1
+//  1.0f - fmin < 1
+//
+// Note: This may fail to be accurate if fast-math has been
+// enabled, as rounding conventions may not apply.
+#ifdef FASTFLOAT_VISUAL_STUDIO
+#pragma warning(push)
+//  todo: is there a VS warning?
+//  see
+//  https://stackoverflow.com/questions/46079446/is-there-a-warning-for-floating-point-equality-checking-in-visual-studio-2013
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wfloat-equal"
+#elif defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+#endif
   return (fmini + 1.0f == 1.0f - fmini);
-  #if FASTFLOAT_VISUAL_STUDIO
-  #   pragma warning(pop)
-  #elif defined(__clang__)
-  #   pragma clang diagnostic pop
-  #elif defined(__GNUC__)
-  #   pragma GCC diagnostic pop
-  #endif
+#ifdef FASTFLOAT_VISUAL_STUDIO
+#pragma warning(pop)
+#elif defined(__clang__)
+#pragma clang diagnostic pop
+#elif defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
 }
 
 } // namespace detail
 
-template<typename T>
-from_chars_result from_chars(const char *first, const char *last,
-                             T &value, chars_format fmt /*= chars_format::general*/)  noexcept  {
-  return from_chars_advanced(first, last, value, parse_options{fmt});
+template <typename T> struct from_chars_caller {
+  template <typename UC>
+  FASTFLOAT_CONSTEXPR20 static from_chars_result_t<UC>
+  call(UC const *first, UC const *last, T &value,
+       parse_options_t<UC> options) noexcept {
+    return from_chars_advanced(first, last, value, options);
+  }
+};
+
+#ifdef __STDCPP_FLOAT32_T__
+template <> struct from_chars_caller<std::float32_t> {
+  template <typename UC>
+  FASTFLOAT_CONSTEXPR20 static from_chars_result_t<UC>
+  call(UC const *first, UC const *last, std::float32_t &value,
+       parse_options_t<UC> options) noexcept {
+    // if std::float32_t is defined, and we are in C++23 mode; macro set for
+    // float32; set value to float due to equivalence between float and
+    // float32_t
+    float val;
+    auto ret = from_chars_advanced(first, last, val, options);
+    value = val;
+    return ret;
+  }
+};
+#endif
+
+#ifdef __STDCPP_FLOAT64_T__
+template <> struct from_chars_caller<std::float64_t> {
+  template <typename UC>
+  FASTFLOAT_CONSTEXPR20 static from_chars_result_t<UC>
+  call(UC const *first, UC const *last, std::float64_t &value,
+       parse_options_t<UC> options) noexcept {
+    // if std::float64_t is defined, and we are in C++23 mode; macro set for
+    // float64; set value as double due to equivalence between double and
+    // float64_t
+    double val;
+    auto ret = from_chars_advanced(first, last, val, options);
+    value = val;
+    return ret;
+  }
+};
+#endif
+
+template <typename T, typename UC, typename>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars(UC const *first, UC const *last, T &value,
+           chars_format fmt /*= chars_format::general*/) noexcept {
+  return from_chars_caller<T>::call(first, last, value,
+                                    parse_options_t<UC>(fmt));
 }
 
-template<typename T>
-from_chars_result from_chars_advanced(const char *first, const char *last,
-                                      T &value, parse_options options)  noexcept  {
+/**
+ * This function overload takes parsed_number_string_t structure that is created
+ * and populated either by from_chars_advanced function taking chars range and
+ * parsing options or other parsing custom function implemented by user.
+ */
+template <typename T, typename UC>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars_advanced(parsed_number_string_t<UC> &pns, T &value) noexcept {
 
-  static_assert (std::is_same<T, double>::value || std::is_same<T, float>::value, "only float and double are supported");
+  static_assert(is_supported_float_type<T>::value,
+                "only some floating-point types are supported");
+  static_assert(is_supported_char_type<UC>::value,
+                "only char, wchar_t, char16_t and char32_t are supported");
 
+  from_chars_result_t<UC> answer;
 
-  from_chars_result answer;
-#if FASTFLOAT_SKIP_WHITE_SPACE  // disabled by default
-  while ((first != last) && fast_float::is_space(uint8_t(*first))) {
-    first++;
-  }
-#endif
-  if (first == last) {
-    answer.ec = std::errc::invalid_argument;
-    answer.ptr = first;
-    return answer;
-  }
-  parsed_number_string pns = parse_number_string(first, last, options);
-  if (!pns.valid) {
-    return detail::parse_infnan(first, last, value);
-  }
   answer.ec = std::errc(); // be optimistic
   answer.ptr = pns.lastmatch;
   // The implementation of the Clinger's fast path is convoluted because
   // we want round-to-nearest in all cases, irrespective of the rounding mode
   // selected on the thread.
-  // We proceed optimistically, assuming that detail::rounds_to_nearest() returns
-  // true.
-  if (binary_format<T>::min_exponent_fast_path() <= pns.exponent && pns.exponent <= binary_format<T>::max_exponent_fast_path() && !pns.too_many_digits) {
+  // We proceed optimistically, assuming that detail::rounds_to_nearest()
+  // returns true.
+  if (binary_format<T>::min_exponent_fast_path() <= pns.exponent &&
+      pns.exponent <= binary_format<T>::max_exponent_fast_path() &&
+      !pns.too_many_digits) {
     // Unfortunately, the conventional Clinger's fast path is only possible
     // when the system rounds to the nearest float.
     //
@@ -165,46 +221,181 @@ from_chars_result from_chars_advanced(const char *first, const char *last,
     // We could check it first (before the previous branch), but
     // there might be performance advantages at having the check
     // be last.
-    if(detail::rounds_to_nearest())  {
+    if (!cpp20_and_in_constexpr() && detail::rounds_to_nearest()) {
       // We have that fegetround() == FE_TONEAREST.
       // Next is Clinger's fast path.
-      if (pns.mantissa <=binary_format<T>::max_mantissa_fast_path()) {
+      if (pns.mantissa <= binary_format<T>::max_mantissa_fast_path()) {
         value = T(pns.mantissa);
-        if (pns.exponent < 0) { value = value / binary_format<T>::exact_power_of_ten(-pns.exponent); }
-        else { value = value * binary_format<T>::exact_power_of_ten(pns.exponent); }
-        if (pns.negative) { value = -value; }
+        if (pns.exponent < 0) {
+          value = value / binary_format<T>::exact_power_of_ten(-pns.exponent);
+        } else {
+          value = value * binary_format<T>::exact_power_of_ten(pns.exponent);
+        }
+        if (pns.negative) {
+          value = -value;
+        }
         return answer;
       }
     } else {
       // We do not have that fegetround() == FE_TONEAREST.
-      // Next is a modified Clinger's fast path, inspired by Jakub Jelínek's proposal
-      if (pns.exponent >= 0 && pns.mantissa <=binary_format<T>::max_mantissa_fast_path(pns.exponent)) {
-#if defined(__clang__)
+      // Next is a modified Clinger's fast path, inspired by Jakub Jelínek's
+      // proposal
+      if (pns.exponent >= 0 &&
+          pns.mantissa <=
+              binary_format<T>::max_mantissa_fast_path(pns.exponent)) {
+#if defined(__clang__) || defined(FASTFLOAT_32BIT)
         // Clang may map 0 to -0.0 when fegetround() == FE_DOWNWARD
-        if(pns.mantissa == 0) {
-          value = 0;
+        if (pns.mantissa == 0) {
+          value = pns.negative ? T(-0.) : T(0.);
           return answer;
         }
 #endif
-        value = T(pns.mantissa) * binary_format<T>::exact_power_of_ten(pns.exponent);
-        if (pns.negative) { value = -value; }
+        value = T(pns.mantissa) *
+                binary_format<T>::exact_power_of_ten(pns.exponent);
+        if (pns.negative) {
+          value = -value;
+        }
         return answer;
       }
     }
   }
-  adjusted_mantissa am = compute_float<binary_format<T>>(pns.exponent, pns.mantissa);
-  if(pns.too_many_digits && am.power2 >= 0) {
-    if(am != compute_float<binary_format<T>>(pns.exponent, pns.mantissa + 1)) {
+  adjusted_mantissa am =
+      compute_float<binary_format<T>>(pns.exponent, pns.mantissa);
+  if (pns.too_many_digits && am.power2 >= 0) {
+    if (am != compute_float<binary_format<T>>(pns.exponent, pns.mantissa + 1)) {
       am = compute_error<binary_format<T>>(pns.exponent, pns.mantissa);
     }
   }
-  // If we called compute_float<binary_format<T>>(pns.exponent, pns.mantissa) and we have an invalid power (am.power2 < 0),
-  // then we need to go the long way around again. This is very uncommon.
-  if(am.power2 < 0) { am = digit_comp<T>(pns, am); }
+  // If we called compute_float<binary_format<T>>(pns.exponent, pns.mantissa)
+  // and we have an invalid power (am.power2 < 0), then we need to go the long
+  // way around again. This is very uncommon.
+  if (am.power2 < 0) {
+    am = digit_comp<T>(pns, am);
+  }
   to_float(pns.negative, am, value);
+  // Test for over/underflow.
+  if ((pns.mantissa != 0 && am.mantissa == 0 && am.power2 == 0) ||
+      am.power2 == binary_format<T>::infinite_power()) {
+    answer.ec = std::errc::result_out_of_range;
+  }
   return answer;
 }
 
+template <typename T, typename UC>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars_float_advanced(UC const *first, UC const *last, T &value,
+                          parse_options_t<UC> options) noexcept {
+
+  static_assert(is_supported_float_type<T>::value,
+                "only some floating-point types are supported");
+  static_assert(is_supported_char_type<UC>::value,
+                "only char, wchar_t, char16_t and char32_t are supported");
+
+  chars_format const fmt = detail::adjust_for_feature_macros(options.format);
+
+  from_chars_result_t<UC> answer;
+  if (uint64_t(fmt & chars_format::skip_white_space)) {
+    while ((first != last) && fast_float::is_space(*first)) {
+      first++;
+    }
+  }
+  if (first == last) {
+    answer.ec = std::errc::invalid_argument;
+    answer.ptr = first;
+    return answer;
+  }
+  parsed_number_string_t<UC> pns =
+      uint64_t(fmt & detail::basic_json_fmt)
+          ? parse_number_string<true, UC>(first, last, options)
+          : parse_number_string<false, UC>(first, last, options);
+  if (!pns.valid) {
+    if (uint64_t(fmt & chars_format::no_infnan)) {
+      answer.ec = std::errc::invalid_argument;
+      answer.ptr = first;
+      return answer;
+    } else {
+      return detail::parse_infnan(first, last, value, fmt);
+    }
+  }
+
+  // call overload that takes parsed_number_string_t directly.
+  return from_chars_advanced(pns, value);
+}
+
+template <typename T, typename UC, typename>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars(UC const *first, UC const *last, T &value, int base) noexcept {
+
+  static_assert(is_supported_integer_type<T>::value,
+                "only integer types are supported");
+  static_assert(is_supported_char_type<UC>::value,
+                "only char, wchar_t, char16_t and char32_t are supported");
+
+  parse_options_t<UC> options;
+  options.base = base;
+  return from_chars_advanced(first, last, value, options);
+}
+
+template <typename T, typename UC>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars_int_advanced(UC const *first, UC const *last, T &value,
+                        parse_options_t<UC> options) noexcept {
+
+  static_assert(is_supported_integer_type<T>::value,
+                "only integer types are supported");
+  static_assert(is_supported_char_type<UC>::value,
+                "only char, wchar_t, char16_t and char32_t are supported");
+
+  chars_format const fmt = detail::adjust_for_feature_macros(options.format);
+  int const base = options.base;
+
+  from_chars_result_t<UC> answer;
+  if (uint64_t(fmt & chars_format::skip_white_space)) {
+    while ((first != last) && fast_float::is_space(*first)) {
+      first++;
+    }
+  }
+  if (first == last || base < 2 || base > 36) {
+    answer.ec = std::errc::invalid_argument;
+    answer.ptr = first;
+    return answer;
+  }
+
+  return parse_int_string(first, last, value, options);
+}
+
+template <size_t TypeIx> struct from_chars_advanced_caller {
+  static_assert(TypeIx > 0, "unsupported type");
+};
+
+template <> struct from_chars_advanced_caller<1> {
+  template <typename T, typename UC>
+  FASTFLOAT_CONSTEXPR20 static from_chars_result_t<UC>
+  call(UC const *first, UC const *last, T &value,
+       parse_options_t<UC> options) noexcept {
+    return from_chars_float_advanced(first, last, value, options);
+  }
+};
+
+template <> struct from_chars_advanced_caller<2> {
+  template <typename T, typename UC>
+  FASTFLOAT_CONSTEXPR20 static from_chars_result_t<UC>
+  call(UC const *first, UC const *last, T &value,
+       parse_options_t<UC> options) noexcept {
+    return from_chars_int_advanced(first, last, value, options);
+  }
+};
+
+template <typename T, typename UC>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars_advanced(UC const *first, UC const *last, T &value,
+                    parse_options_t<UC> options) noexcept {
+  return from_chars_advanced_caller<
+      size_t(is_supported_float_type<T>::value) +
+      2 * size_t(is_supported_integer_type<T>::value)>::call(first, last, value,
+                                                             options);
+}
+
 } // namespace fast_float
 
 #endif

ThirdParty/fast_float/vtkfast_float/vtkfast_float/simple_decimal_conversion.h

-#ifndef FASTFLOAT_GENERIC_DECIMAL_TO_BINARY_H
-#define FASTFLOAT_GENERIC_DECIMAL_TO_BINARY_H
-
-/**
- * This code is meant to handle the case where we have more than 19 digits.
- *
- * It is based on work by Nigel Tao (at https://github.com/google/wuffs/)
- * who credits Ken Thompson for the design (via a reference to the Go source
- * code).
- *
- * Rob Pike suggested that this algorithm be called "Simple Decimal Conversion".
- *
- * It is probably not very fast but it is a fallback that should almost never
- * be used in real life. Though it is not fast, it is "easily" understood and debugged.
- **/
-#include "ascii_number.h"
-#include "decimal_to_binary.h"
-#include <cstdint>
-
-namespace fast_float {
-
-namespace detail {
-
-// remove all final zeroes
-inline void trim(decimal &h) {
-  while ((h.num_digits > 0) && (h.digits[h.num_digits - 1] == 0)) {
-    h.num_digits--;
-  }
-}
-
-
-
-inline uint32_t number_of_digits_decimal_left_shift(const decimal &h, uint32_t shift) {
-  shift &= 63;
-  constexpr uint16_t number_of_digits_decimal_left_shift_table[65] = {
-    0x0000, 0x0800, 0x0801, 0x0803, 0x1006, 0x1009, 0x100D, 0x1812, 0x1817,
-    0x181D, 0x2024, 0x202B, 0x2033, 0x203C, 0x2846, 0x2850, 0x285B, 0x3067,
-    0x3073, 0x3080, 0x388E, 0x389C, 0x38AB, 0x38BB, 0x40CC, 0x40DD, 0x40EF,
-    0x4902, 0x4915, 0x4929, 0x513E, 0x5153, 0x5169, 0x5180, 0x5998, 0x59B0,
-    0x59C9, 0x61E3, 0x61FD, 0x6218, 0x6A34, 0x6A50, 0x6A6D, 0x6A8B, 0x72AA,
-    0x72C9, 0x72E9, 0x7B0A, 0x7B2B, 0x7B4D, 0x8370, 0x8393, 0x83B7, 0x83DC,
-    0x8C02, 0x8C28, 0x8C4F, 0x9477, 0x949F, 0x94C8, 0x9CF2, 0x051C, 0x051C,
-    0x051C, 0x051C,
-  };
-  uint32_t x_a = number_of_digits_decimal_left_shift_table[shift];
-  uint32_t x_b = number_of_digits_decimal_left_shift_table[shift + 1];
-  uint32_t num_new_digits = x_a >> 11;
-  uint32_t pow5_a = 0x7FF & x_a;
-  uint32_t pow5_b = 0x7FF & x_b;
-  constexpr uint8_t
-    number_of_digits_decimal_left_shift_table_powers_of_5[0x051C] = {
-        5, 2, 5, 1, 2, 5, 6, 2, 5, 3, 1, 2, 5, 1, 5, 6, 2, 5, 7, 8, 1, 2, 5, 3,
-        9, 0, 6, 2, 5, 1, 9, 5, 3, 1, 2, 5, 9, 7, 6, 5, 6, 2, 5, 4, 8, 8, 2, 8,
-        1, 2, 5, 2, 4, 4, 1, 4, 0, 6, 2, 5, 1, 2, 2, 0, 7, 0, 3, 1, 2, 5, 6, 1,
-        0, 3, 5, 1, 5, 6, 2, 5, 3, 0, 5, 1, 7, 5, 7, 8, 1, 2, 5, 1, 5, 2, 5, 8,
-        7, 8, 9, 0, 6, 2, 5, 7, 6, 2, 9, 3, 9, 4, 5, 3, 1, 2, 5, 3, 8, 1, 4, 6,
-        9, 7, 2, 6, 5, 6, 2, 5, 1, 9, 0, 7, 3, 4, 8, 6, 3, 2, 8, 1, 2, 5, 9, 5,
-        3, 6, 7, 4, 3, 1, 6, 4, 0, 6, 2, 5, 4, 7, 6, 8, 3, 7, 1, 5, 8, 2, 0, 3,
-        1, 2, 5, 2, 3, 8, 4, 1, 8, 5, 7, 9, 1, 0, 1, 5, 6, 2, 5, 1, 1, 9, 2, 0,
-        9, 2, 8, 9, 5, 5, 0, 7, 8, 1, 2, 5, 5, 9, 6, 0, 4, 6, 4, 4, 7, 7, 5, 3,
-        9, 0, 6, 2, 5, 2, 9, 8, 0, 2, 3, 2, 2, 3, 8, 7, 6, 9, 5, 3, 1, 2, 5, 1,
-        4, 9, 0, 1, 1, 6, 1, 1, 9, 3, 8, 4, 7, 6, 5, 6, 2, 5, 7, 4, 5, 0, 5, 8,
-        0, 5, 9, 6, 9, 2, 3, 8, 2, 8, 1, 2, 5, 3, 7, 2, 5, 2, 9, 0, 2, 9, 8, 4,
-        6, 1, 9, 1, 4, 0, 6, 2, 5, 1, 8, 6, 2, 6, 4, 5, 1, 4, 9, 2, 3, 0, 9, 5,
-        7, 0, 3, 1, 2, 5, 9, 3, 1, 3, 2, 2, 5, 7, 4, 6, 1, 5, 4, 7, 8, 5, 1, 5,
-        6, 2, 5, 4, 6, 5, 6, 6, 1, 2, 8, 7, 3, 0, 7, 7, 3, 9, 2, 5, 7, 8, 1, 2,
-        5, 2, 3, 2, 8, 3, 0, 6, 4, 3, 6, 5, 3, 8, 6, 9, 6, 2, 8, 9, 0, 6, 2, 5,
-        1, 1, 6, 4, 1, 5, 3, 2, 1, 8, 2, 6, 9, 3, 4, 8, 1, 4, 4, 5, 3, 1, 2, 5,
-        5, 8, 2, 0, 7, 6, 6, 0, 9, 1, 3, 4, 6, 7, 4, 0, 7, 2, 2, 6, 5, 6, 2, 5,
-        2, 9, 1, 0, 3, 8, 3, 0, 4, 5, 6, 7, 3, 3, 7, 0, 3, 6, 1, 3, 2, 8, 1, 2,
-        5, 1, 4, 5, 5, 1, 9, 1, 5, 2, 2, 8, 3, 6, 6, 8, 5, 1, 8, 0, 6, 6, 4, 0,
-        6, 2, 5, 7, 2, 7, 5, 9, 5, 7, 6, 1, 4, 1, 8, 3, 4, 2, 5, 9, 0, 3, 3, 2,
-        0, 3, 1, 2, 5, 3, 6, 3, 7, 9, 7, 8, 8, 0, 7, 0, 9, 1, 7, 1, 2, 9, 5, 1,
-        6, 6, 0, 1, 5, 6, 2, 5, 1, 8, 1, 8, 9, 8, 9, 4, 0, 3, 5, 4, 5, 8, 5, 6,
-        4, 7, 5, 8, 3, 0, 0, 7, 8, 1, 2, 5, 9, 0, 9, 4, 9, 4, 7, 0, 1, 7, 7, 2,
-        9, 2, 8, 2, 3, 7, 9, 1, 5, 0, 3, 9, 0, 6, 2, 5, 4, 5, 4, 7, 4, 7, 3, 5,
-        0, 8, 8, 6, 4, 6, 4, 1, 1, 8, 9, 5, 7, 5, 1, 9, 5, 3, 1, 2, 5, 2, 2, 7,
-        3, 7, 3, 6, 7, 5, 4, 4, 3, 2, 3, 2, 0, 5, 9, 4, 7, 8, 7, 5, 9, 7, 6, 5,
-        6, 2, 5, 1, 1, 3, 6, 8, 6, 8, 3, 7, 7, 2, 1, 6, 1, 6, 0, 2, 9, 7, 3, 9,
-        3, 7, 9, 8, 8, 2, 8, 1, 2, 5, 5, 6, 8, 4, 3, 4, 1, 8, 8, 6, 0, 8, 0, 8,
-        0, 1, 4, 8, 6, 9, 6, 8, 9, 9, 4, 1, 4, 0, 6, 2, 5, 2, 8, 4, 2, 1, 7, 0,
-        9, 4, 3, 0, 4, 0, 4, 0, 0, 7, 4, 3, 4, 8, 4, 4, 9, 7, 0, 7, 0, 3, 1, 2,
-        5, 1, 4, 2, 1, 0, 8, 5, 4, 7, 1, 5, 2, 0, 2, 0, 0, 3, 7, 1, 7, 4, 2, 2,
-        4, 8, 5, 3, 5, 1, 5, 6, 2, 5, 7, 1, 0, 5, 4, 2, 7, 3, 5, 7, 6, 0, 1, 0,
-        0, 1, 8, 5, 8, 7, 1, 1, 2, 4, 2, 6, 7, 5, 7, 8, 1, 2, 5, 3, 5, 5, 2, 7,
-        1, 3, 6, 7, 8, 8, 0, 0, 5, 0, 0, 9, 2, 9, 3, 5, 5, 6, 2, 1, 3, 3, 7, 8,
-        9, 0, 6, 2, 5, 1, 7, 7, 6, 3, 5, 6, 8, 3, 9, 4, 0, 0, 2, 5, 0, 4, 6, 4,
-        6, 7, 7, 8, 1, 0, 6, 6, 8, 9, 4, 5, 3, 1, 2, 5, 8, 8, 8, 1, 7, 8, 4, 1,
-        9, 7, 0, 0, 1, 2, 5, 2, 3, 2, 3, 3, 8, 9, 0, 5, 3, 3, 4, 4, 7, 2, 6, 5,
-        6, 2, 5, 4, 4, 4, 0, 8, 9, 2, 0, 9, 8, 5, 0, 0, 6, 2, 6, 1, 6, 1, 6, 9,
-        4, 5, 2, 6, 6, 7, 2, 3, 6, 3, 2, 8, 1, 2, 5, 2, 2, 2, 0, 4, 4, 6, 0, 4,
-        9, 2, 5, 0, 3, 1, 3, 0, 8, 0, 8, 4, 7, 2, 6, 3, 3, 3, 6, 1, 8, 1, 6, 4,
-        0, 6, 2, 5, 1, 1, 1, 0, 2, 2, 3, 0, 2, 4, 6, 2, 5, 1, 5, 6, 5, 4, 0, 4,
-        2, 3, 6, 3, 1, 6, 6, 8, 0, 9, 0, 8, 2, 0, 3, 1, 2, 5, 5, 5, 5, 1, 1, 1,
-        5, 1, 2, 3, 1, 2, 5, 7, 8, 2, 7, 0, 2, 1, 1, 8, 1, 5, 8, 3, 4, 0, 4, 5,
-        4, 1, 0, 1, 5, 6, 2, 5, 2, 7, 7, 5, 5, 5, 7, 5, 6, 1, 5, 6, 2, 8, 9, 1,
-        3, 5, 1, 0, 5, 9, 0, 7, 9, 1, 7, 0, 2, 2, 7, 0, 5, 0, 7, 8, 1, 2, 5, 1,
-        3, 8, 7, 7, 7, 8, 7, 8, 0, 7, 8, 1, 4, 4, 5, 6, 7, 5, 5, 2, 9, 5, 3, 9,
-        5, 8, 5, 1, 1, 3, 5, 2, 5, 3, 9, 0, 6, 2, 5, 6, 9, 3, 8, 8, 9, 3, 9, 0,
-        3, 9, 0, 7, 2, 2, 8, 3, 7, 7, 6, 4, 7, 6, 9, 7, 9, 2, 5, 5, 6, 7, 6, 2,
-        6, 9, 5, 3, 1, 2, 5, 3, 4, 6, 9, 4, 4, 6, 9, 5, 1, 9, 5, 3, 6, 1, 4, 1,
-        8, 8, 8, 2, 3, 8, 4, 8, 9, 6, 2, 7, 8, 3, 8, 1, 3, 4, 7, 6, 5, 6, 2, 5,
-        1, 7, 3, 4, 7, 2, 3, 4, 7, 5, 9, 7, 6, 8, 0, 7, 0, 9, 4, 4, 1, 1, 9, 2,
-        4, 4, 8, 1, 3, 9, 1, 9, 0, 6, 7, 3, 8, 2, 8, 1, 2, 5, 8, 6, 7, 3, 6, 1,
-        7, 3, 7, 9, 8, 8, 4, 0, 3, 5, 4, 7, 2, 0, 5, 9, 6, 2, 2, 4, 0, 6, 9, 5,
-        9, 5, 3, 3, 6, 9, 1, 4, 0, 6, 2, 5,
-  };
-  const uint8_t *pow5 =
-      &number_of_digits_decimal_left_shift_table_powers_of_5[pow5_a];
-  uint32_t i = 0;
-  uint32_t n = pow5_b - pow5_a;
-  for (; i < n; i++) {
-    if (i >= h.num_digits) {
-      return num_new_digits - 1;
-    } else if (h.digits[i] == pow5[i]) {
-      continue;
-    } else if (h.digits[i] < pow5[i]) {
-      return num_new_digits - 1;
-    } else {
-      return num_new_digits;
-    }
-  }
-  return num_new_digits;
-}
-
-inline uint64_t round(decimal &h) {
-  if ((h.num_digits == 0) || (h.decimal_point < 0)) {
-    return 0;
-  } else if (h.decimal_point > 18) {
-    return UINT64_MAX;
-  }
-  // at this point, we know that h.decimal_point >= 0
-  uint32_t dp = uint32_t(h.decimal_point);
-  uint64_t n = 0;
-  for (uint32_t i = 0; i < dp; i++) {
-    n = (10 * n) + ((i < h.num_digits) ? h.digits[i] : 0);
-  }
-  bool round_up = false;
-  if (dp < h.num_digits) {
-    round_up = h.digits[dp] >= 5; // normally, we round up
-    // but we may need to round to even!
-    if ((h.digits[dp] == 5) && (dp + 1 == h.num_digits)) {
-      round_up = h.truncated || ((dp > 0) && (1 & h.digits[dp - 1]));
-    }
-  }
-  if (round_up) {
-    n++;
-  }
-  return n;
-}
-
-// computes h * 2^-shift
-inline void decimal_left_shift(decimal &h, uint32_t shift) {
-  if (h.num_digits == 0) {
-    return;
-  }
-  uint32_t num_new_digits = number_of_digits_decimal_left_shift(h, shift);
-  int32_t read_index = int32_t(h.num_digits - 1);
-  uint32_t write_index = h.num_digits - 1 + num_new_digits;
-  uint64_t n = 0;
-
-  while (read_index >= 0) {
-    n += uint64_t(h.digits[read_index]) << shift;
-    uint64_t quotient = n / 10;
-    uint64_t remainder = n - (10 * quotient);
-    if (write_index < max_digits) {
-      h.digits[write_index] = uint8_t(remainder);
-    } else if (remainder > 0) {
-      h.truncated = true;
-    }
-    n = quotient;
-    write_index--;
-    read_index--;
-  }
-  while (n > 0) {
-    uint64_t quotient = n / 10;
-    uint64_t remainder = n - (10 * quotient);
-    if (write_index < max_digits) {
-      h.digits[write_index] = uint8_t(remainder);
-    } else if (remainder > 0) {
-      h.truncated = true;
-    }
-    n = quotient;
-    write_index--;
-  }
-  h.num_digits += num_new_digits;
-  if (h.num_digits > max_digits) {
-    h.num_digits = max_digits;
-  }
-  h.decimal_point += int32_t(num_new_digits);
-  trim(h);
-}
-
-// computes h * 2^shift
-inline void decimal_right_shift(decimal &h, uint32_t shift) {
-  uint32_t read_index = 0;
-  uint32_t write_index = 0;
-
-  uint64_t n = 0;
-
-  while ((n >> shift) == 0) {
-    if (read_index < h.num_digits) {
-      n = (10 * n) + h.digits[read_index++];
-    } else if (n == 0) {
-      return;
-    } else {
-      while ((n >> shift) == 0) {
-        n = 10 * n;
-        read_index++;
-      }
-      break;
-    }
-  }
-  h.decimal_point -= int32_t(read_index - 1);
-  if (h.decimal_point < -decimal_point_range) { // it is zero
-    h.num_digits = 0;
-    h.decimal_point = 0;
-    h.negative = false;
-    h.truncated = false;
-    return;
-  }
-  uint64_t mask = (uint64_t(1) << shift) - 1;
-  while (read_index < h.num_digits) {
-    uint8_t new_digit = uint8_t(n >> shift);
-    n = (10 * (n & mask)) + h.digits[read_index++];
-    h.digits[write_index++] = new_digit;
-  }
-  while (n > 0) {
-    uint8_t new_digit = uint8_t(n >> shift);
-    n = 10 * (n & mask);
-    if (write_index < max_digits) {
-      h.digits[write_index++] = new_digit;
-    } else if (new_digit > 0) {
-      h.truncated = true;
-    }
-  }
-  h.num_digits = write_index;
-  trim(h);
-}
-
-} // namespace detail
-
-template <typename binary>
-adjusted_mantissa compute_float(decimal &d) {
-  adjusted_mantissa answer;
-  if (d.num_digits == 0) {
-    // should be zero
-    answer.power2 = 0;
-    answer.mantissa = 0;
-    return answer;
-  }
-  // At this point, going further, we can assume that d.num_digits > 0.
-  //
-  // We want to guard against excessive decimal point values because
-  // they can result in long running times. Indeed, we do
-  // shifts by at most 60 bits. We have that log(10**400)/log(2**60) ~= 22
-  // which is fine, but log(10**299995)/log(2**60) ~= 16609 which is not
-  // fine (runs for a long time).
-  //
-  if(d.decimal_point < -324) {
-    // We have something smaller than 1e-324 which is always zero
-    // in binary64 and binary32.
-    // It should be zero.
-    answer.power2 = 0;
-    answer.mantissa = 0;
-    return answer;
-  } else if(d.decimal_point >= 310) {
-    // We have something at least as large as 0.1e310 which is
-    // always infinite.
-    answer.power2 = binary::infinite_power();
-    answer.mantissa = 0;
-    return answer;
-  }
-  constexpr uint32_t max_shift = 60;
-  constexpr uint32_t num_powers = 19;
-  constexpr uint8_t decimal_powers[19] = {
-      0,  3,  6,  9,  13, 16, 19, 23, 26, 29, //
-      33, 36, 39, 43, 46, 49, 53, 56, 59,     //
-  };
-  int32_t exp2 = 0;
-  while (d.decimal_point > 0) {
-    uint32_t n = uint32_t(d.decimal_point);
-    uint32_t shift = (n < num_powers) ? decimal_powers[n] : max_shift;
-    detail::decimal_right_shift(d, shift);
-    if (d.decimal_point < -decimal_point_range) {
-      // should be zero
-      answer.power2 = 0;
-      answer.mantissa = 0;
-      return answer;
-    }
-    exp2 += int32_t(shift);
-  }
-  // We shift left toward [1/2 ... 1].
-  while (d.decimal_point <= 0) {
-    uint32_t shift;
-    if (d.decimal_point == 0) {
-      if (d.digits[0] >= 5) {
-        break;
-      }
-      shift = (d.digits[0] < 2) ? 2 : 1;
-    } else {
-      uint32_t n = uint32_t(-d.decimal_point);
-      shift = (n < num_powers) ? decimal_powers[n] : max_shift;
-    }
-    detail::decimal_left_shift(d, shift);
-    if (d.decimal_point > decimal_point_range) {
-      // we want to get infinity:
-      answer.power2 = binary::infinite_power();
-      answer.mantissa = 0;
-      return answer;
-    }
-    exp2 -= int32_t(shift);
-  }
-  // We are now in the range [1/2 ... 1] but the binary format uses [1 ... 2].
-  exp2--;
-  constexpr int32_t minimum_exponent = binary::minimum_exponent();
-  while ((minimum_exponent + 1) > exp2) {
-    uint32_t n = uint32_t((minimum_exponent + 1) - exp2);
-    if (n > max_shift) {
-      n = max_shift;
-    }
-    detail::decimal_right_shift(d, n);
-    exp2 += int32_t(n);
-  }
-  if ((exp2 - minimum_exponent) >= binary::infinite_power()) {
-    answer.power2 = binary::infinite_power();
-    answer.mantissa = 0;
-    return answer;
-  }
-
-  const int mantissa_size_in_bits = binary::mantissa_explicit_bits() + 1;
-  detail::decimal_left_shift(d, mantissa_size_in_bits);
-
-  uint64_t mantissa = detail::round(d);
-  // It is possible that we have an overflow, in which case we need
-  // to shift back.
-  if(mantissa >= (uint64_t(1) << mantissa_size_in_bits)) {
-    detail::decimal_right_shift(d, 1);
-    exp2 += 1;
-    mantissa = detail::round(d);
-    if ((exp2 - minimum_exponent) >= binary::infinite_power()) {
-      answer.power2 = binary::infinite_power();
-      answer.mantissa = 0;
-      return answer;
-    }
-  }
-  answer.power2 = exp2  - binary::minimum_exponent();
-  if(mantissa < (uint64_t(1) << binary::mantissa_explicit_bits())) { answer.power2--; }
-  answer.mantissa = mantissa & ((uint64_t(1) << binary::mantissa_explicit_bits()) - 1);
-  return answer;
-}
-
-template <typename binary>
-adjusted_mantissa parse_long_mantissa(const char *first, const char* last, parse_options options) {
-    decimal d = parse_decimal(first, last, options);
-    return compute_float<binary>(d);
-}
-
-} // namespace fast_float
-#endif