cleanup and type usage fixes.

Author: IRainman

include/fast_float/ascii_number.h

@@ -291,9 +291,6 @@ template <bool basic_json_fmt, typename UC>
 fastfloat_really_inline FASTFLOAT_CONSTEXPR20 parsed_number_string_t<UC>
 parse_number_string(UC const *p, UC const *pend,
                     parse_options_t<UC> const options) noexcept {
-  // Cyclomatic complexity https://en.wikipedia.org/wiki/Cyclomatic_complexity
-  // Consider refactoring the 'parse_number_string' function.
-  // FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN fix this.
   parsed_number_string_t<UC> answer;
   // so dereference without checks
   FASTFLOAT_ASSUME(p < pend);
@@ -460,12 +457,12 @@ parse_number_string(UC const *p, UC const *pend,
 
   // Now we can check for errors.
 
-  // TODO: If we frequently had to deal with long strings of digits,
+  // If we frequently had to deal with long strings of digits,
   // we could extend our code by using a 128-bit integer instead
   // of a 64-bit integer. However, this is uncommon.
-
+  //
   // We can deal with up to 19 digits.
-  if (digit_count > 19) {
+  if (digit_count > 19) { // this is uncommon
     // It is possible that the integer had an overflow.
     // We have to handle the case where we have 0.0000somenumber.
     // We need to be mindful of the case where we only have zeroes...
@@ -479,8 +476,7 @@ parse_number_string(UC const *p, UC const *pend,
       ++start;
     }
 
-    // We have to check if we have a number with more than 19 significant
-    // digits.
+    // We have to check if number has more than 19 significant digits.
     if (digit_count > 19) {
       answer.too_many_digits = true;
       // Let us start again, this time, avoiding overflows.
@@ -492,8 +488,8 @@ parse_number_string(UC const *p, UC const *pend,
       constexpr am_mant_t minimal_nineteen_digit_integer{1000000000000000000};
       while ((p != int_end) &&
              (answer.mantissa < minimal_nineteen_digit_integer)) {
-        answer.mantissa = static_cast<am_mant_t>(
-            answer.mantissa * 10 + static_cast<am_mant_t>(*p - UC('0')));
+        answer.mantissa =
+            answer.mantissa * 10 + static_cast<am_mant_t>(*p - UC('0'));
         ++p;
       }
       if (answer.mantissa >= minimal_nineteen_digit_integer) {

include/fast_float/bigint.h

@@ -67,7 +67,7 @@ template <limb_t size> struct stackvec {
   // index from the end of the container
   FASTFLOAT_CONSTEXPR14 const limb &rindex(limb_t index) const noexcept {
     FASTFLOAT_DEBUG_ASSERT(index < length);
-    limb_t rindex = static_cast<limb_t>(length - index - 1);
+    auto rindex = length - index - 1;
     return data[rindex];
   }
 
@@ -100,7 +100,7 @@ template <limb_t size> struct stackvec {
   FASTFLOAT_CONSTEXPR20 void extend_unchecked(limb_span s) noexcept {
     limb *ptr = data + length;
     std::copy_n(s.ptr, s.len(), ptr);
-    set_len(static_cast<limb_t>(len() + s.len()));
+    set_len(len() + static_cast<limb_t>(s.len()));
   }
 
   // try to add items to the vector, returning if items were added
@@ -119,7 +119,7 @@ template <limb_t size> struct stackvec {
   FASTFLOAT_CONSTEXPR20
   void resize_unchecked(limb_t new_len, limb value) noexcept {
     if (new_len > len()) {
-      limb_t count = new_len - len();
+      auto count = new_len - len();
       limb *first = data + len();
       limb *last = first + count;
       ::std::fill(first, last, value);
@@ -258,9 +258,8 @@ scalar_mul(limb x, limb y, limb &carry) noexcept {
 // add scalar value to bigint starting from offset.
 // used in grade school multiplication
 template <limb_t size>
-inline FASTFLOAT_CONSTEXPR20 bool small_add_from(stackvec<size> &vec, limb y,
-                                                 limb_t start) noexcept {
-  limb carry = y;
+inline FASTFLOAT_CONSTEXPR20 bool
+small_add_from(stackvec<size> &vec, limb carry, limb_t start) noexcept {
   bool overflow;
   while (carry != 0 && start < vec.len()) {
     vec[start] = scalar_add(vec[start], carry, overflow);
@@ -301,8 +300,9 @@ FASTFLOAT_CONSTEXPR20 bool large_add_from(stackvec<size> &x, limb_span y,
                                           limb_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() > static_cast<limb_t>(x.len() - start)) {
-    FASTFLOAT_TRY(x.try_resize(static_cast<limb_t>(y.len() + start), 0));
+  if (x.len() < start ||
+      y.len() > static_cast<uint_fast16_t>(x.len() - start)) {
+    FASTFLOAT_TRY(x.try_resize(static_cast<limb_t>(y.len()) + start, 0));
   }
 
   bool carry = false;
@@ -321,7 +321,7 @@ FASTFLOAT_CONSTEXPR20 bool large_add_from(stackvec<size> &x, limb_span y,
 
   // handle overflow
   if (carry) {
-    FASTFLOAT_TRY(small_add_from(x, 1, static_cast<limb_t>(y.len() + start)));
+    FASTFLOAT_TRY(small_add_from(x, 1, static_cast<limb_t>(y.len()) + start));
   }
   return true;
 }
@@ -343,7 +343,7 @@ FASTFLOAT_CONSTEXPR20 bool long_mul(stackvec<size> &x, limb_span y) noexcept {
   if (y.len() != 0) {
     limb y0 = y[0];
     FASTFLOAT_TRY(small_mul(x, y0));
-    for (limb_t index = 1; index != y.len(); ++index) {
+    for (limb_t index = 1; index < y.len(); ++index) {
       limb yi = y[index];
       stackvec<size> zi;
       if (yi != 0) {
@@ -584,8 +584,8 @@ struct bigint : pow5_tables<> {
 
   // get the number of bits in the bigint.
   FASTFLOAT_CONSTEXPR20 bigint_bits_t bit_length() const noexcept {
-    bigint_bits_t lz = ctlz();
-    return static_cast<fast_float::bigint_bits_t>(limb_bits * vec.len() - lz);
+    auto lz = ctlz();
+    return limb_bits * vec.len() - lz;
   }
 
   FASTFLOAT_CONSTEXPR20 bool mul(limb y) noexcept { return small_mul(vec, y); }

include/fast_float/constexpr_feature_detect.h

@@ -76,15 +76,6 @@
 #define FASTFLOAT_INLINE_VARIABLE static constexpr
 #endif
 
-#if defined(__cpp_lib_is_constant_evaluated) &&                                \
-    __cpp_lib_is_constant_evaluated >= 201811L
-#define FASTFLOAT_HAS_IS_CONSTANT_EVALUATED 1
-#define FASTFLOAT_CONSTEVAL consteval
-#else
-#define FASTFLOAT_HAS_IS_CONSTANT_EVALUATED 0
-#define FASTFLOAT_CONSTEVAL FASTFLOAT_CONSTEXPR14
-#endif
-
 // Testing for relevant C++20 constexpr library features
 #if FASTFLOAT_HAS_IS_CONSTANT_EVALUATED && FASTFLOAT_HAS_BIT_CAST &&           \
     defined(__cpp_lib_constexpr_algorithms) &&                                 \

include/fast_float/decimal_to_binary.h

@@ -72,7 +72,7 @@ constexpr fastfloat_really_inline am_pow_t power(am_pow_t q) noexcept {
 template <typename binary>
 fastfloat_really_inline FASTFLOAT_CONSTEXPR14 adjusted_mantissa
 compute_error_scaled(am_pow_t q, am_mant_t w, am_bits_t lz) noexcept {
-  auto const hilz = static_cast<am_pow_t>((w >> 63) ^ 1);
+  auto const hilz = static_cast<am_bits_t>((w >> 63) ^ 1);
   adjusted_mantissa answer;
   answer.mantissa = w << hilz;
   constexpr am_pow_t bias =
@@ -138,8 +138,8 @@ compute_float(am_pow_t q, am_mant_t w) noexcept {
   // 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.
-  auto const upperbit = static_cast<limb_t>(product.high >> 63);
-  limb_t const shift = upperbit + 64 - binary::mantissa_explicit_bits() - 3;
+  auto const upperbit = static_cast<am_bits_t>(product.high >> 63);
+  am_bits_t const shift = upperbit + 64 - binary::mantissa_explicit_bits() - 3;
 
   answer.mantissa = product.high >> shift;
 

include/fast_float/digit_comparison.h

@@ -68,7 +68,7 @@ to_extended(T const value) noexcept {
   constexpr am_pow_t bias = binary_format<T>::mantissa_explicit_bits() -
                             binary_format<T>::minimum_exponent();
 
-  equiv_uint const bits = bit_cast<equiv_uint, T>(value);
+  auto const bits = bit_cast<equiv_uint, T>(value);
 
   if ((bits & exponent_mask) == 0) {
     // denormal

include/fast_float/float_common.h

@@ -49,19 +49,19 @@ typedef uint_fast8_t limb_t;
 typedef int_fast8_t am_bits_t;
 
 // 16 bit signed integer is used for power to cover all double exponents.
-typedef int16_t am_pow_t;
+typedef int_fast16_t am_pow_t;
 // Power bias is signed for handling a denormal float
 // or an invalid mantissa.
 // Bias so we can get the real exponent with an invalid adjusted_mantissa.
 constexpr static am_pow_t invalid_am_bias =
-    std::numeric_limits<am_pow_t>::min() + 1;
+    std::numeric_limits<int16_t>::min() + 1;
 constexpr static am_pow_t am_bias_limit =
-    (std::numeric_limits<am_pow_t>::max() / 8) - 1;
+    (std::numeric_limits<int16_t>::max() / 16) - 1;
 
 // Type for enum chars_format.
 typedef uint_fast8_t chars_format_t;
 
-// Type for base.
+// Type for base, only allowed from 2 to 36.
 typedef uint_fast8_t base_t;
 
 enum class chars_format : chars_format_t;
@@ -110,10 +110,10 @@ template <typename UC> struct parse_options_t {
 
   /** Which number formats are accepted */
   chars_format format;
-  /** The character used as decimal point */
+  /** The character used as decimal point for floats */
   UC decimal_point;
   /** The base used for integers */
-  base_t base; /* only allowed from 2 to 36 */
+  base_t base;
 };
 
 using parse_options = parse_options_t<char>;