DX-61115: [C++] Update fast_float version to 3.10.1 (#36434)

cpp/src/arrow/util/value_parsing.cc

@@ -15,6 +15,8 @@
 // specific language governing permissions and limitations
 // under the License.
 
+#define FASTFLOAT_ALLOWS_LEADING_PLUS 1
+
 #include "arrow/util/value_parsing.h"
 
 #include <string>

cpp/src/arrow/util/value_parsing_test.cc

@@ -119,6 +119,9 @@ TEST(StringConversion, ToFloat) {
   AssertConversion<FloatType>("0", 0.0f);
   AssertConversion<FloatType>("-0.0", -0.0f);
   AssertConversion<FloatType>("-1e20", -1e20f);
+  AssertConversion<FloatType>("+Infinity", std::numeric_limits<float>::infinity());
+  AssertConversion<FloatType>("-Infinity", -std::numeric_limits<float>::infinity());
+  AssertConversion<FloatType>("Infinity", std::numeric_limits<float>::infinity());
 
   AssertConversionFails<FloatType>("");
   AssertConversionFails<FloatType>("e");
@@ -135,6 +138,9 @@ TEST(StringConversion, ToDouble) {
   AssertConversion<DoubleType>("0", 0);
   AssertConversion<DoubleType>("-0.0", -0.0);
   AssertConversion<DoubleType>("-1e100", -1e100);
+  AssertConversion<DoubleType>("+Infinity", std::numeric_limits<double>::infinity());
+  AssertConversion<DoubleType>("-Infinity", -std::numeric_limits<double>::infinity());
+  AssertConversion<DoubleType>("Infinity", std::numeric_limits<double>::infinity());
 
   AssertConversionFails<DoubleType>("");
   AssertConversionFails<DoubleType>("e");

cpp/src/arrow/vendored/fast_float/README.md

@@ -20,7 +20,7 @@
 # fast_float
 
 The files in this directory are vendored from fast_float
-git tag `v3.8.1`.
+git tag `v3.10.1`.
 
 See https://github.com/fastfloat/fast_float
 
@@ -31,7 +31,7 @@ See https://github.com/fastfloat/fast_float
 ## How to update
 
 You must replace `VERSION` in the command lines with suitable version
-such as `3.8.1`.
+such as `3.10.1`.
 
 ```bash
 cpp/src/arrow/vendoered/fast_float/update.sh VERSION

cpp/src/arrow/vendored/fast_float/ascii_number.h

@@ -13,9 +13,11 @@ namespace fast_float {
 
 // Next function can be micro-optimized, but compilers are entirely
 // able to optimize it well.
-fastfloat_really_inline bool is_integer(char c)  noexcept  { return c >= '0' && c <= '9'; }
+fastfloat_really_inline constexpr bool is_integer(char c) noexcept {
+  return c >= '0' && c <= '9';
+}
 
-fastfloat_really_inline uint64_t byteswap(uint64_t val) {
+fastfloat_really_inline constexpr uint64_t byteswap(uint64_t val) {
   return (val & 0xFF00000000000000) >> 56
     | (val & 0x00FF000000000000) >> 40
     | (val & 0x0000FF0000000000) >> 24
@@ -45,7 +47,8 @@ fastfloat_really_inline void write_u64(uint8_t *chars, uint64_t val) {
 }
 
 // credit  @aqrit
-fastfloat_really_inline uint32_t  parse_eight_digits_unrolled(uint64_t val) {
+fastfloat_really_inline FASTFLOAT_CONSTEXPR14
+uint32_t parse_eight_digits_unrolled(uint64_t val) {
   const uint64_t mask = 0x000000FF000000FF;
   const uint64_t mul1 = 0x000F424000000064; // 100 + (1000000ULL << 32)
   const uint64_t mul2 = 0x0000271000000001; // 1 + (10000ULL << 32)
@@ -60,7 +63,7 @@ fastfloat_really_inline uint32_t parse_eight_digits_unrolled(const char *chars)
 }
 
 // credit @aqrit
-fastfloat_really_inline bool is_made_of_eight_digits_fast(uint64_t val)  noexcept  {
+fastfloat_really_inline constexpr bool is_made_of_eight_digits_fast(uint64_t val)  noexcept  {
   return !((((val + 0x4646464646464646) | (val - 0x3030303030303030)) &
      0x8080808080808080));
 }
@@ -94,7 +97,11 @@ parsed_number_string parse_number_string(const char *p, const char *pend, parse_
   answer.valid = false;
   answer.too_many_digits = false;
   answer.negative = (*p == '-');
+#if FASTFLOAT_ALLOWS_LEADING_PLUS // disabled by default
+  if ((*p == '-') || (*p == '+')) {
+#else
   if (*p == '-') { // C++17 20.19.3.(7.1) explicitly forbids '+' sign here
+#endif
     ++p;
     if (p == pend) {
       return answer;