added template overload for integer_times_pow10()

Author: toughengineer

include/fast_float/fast_float.h

@@ -63,6 +63,20 @@ integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept;
 FASTFLOAT_CONSTEXPR20 inline double
 integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept;
 
+/**
+ * This function is a template overload of `integer_times_pow10()`
+ * that returns a floating-point value of type `T` that is one of
+ * supported floating-point types (e.g. `double`, `float`).
+ */
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept;
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept;
+
 /**
  * from_chars for integer types.
  */

include/fast_float/parse_number.h

@@ -344,44 +344,79 @@ from_chars(UC const *first, UC const *last, T &value, int base) noexcept {
   return from_chars_advanced(first, last, value, options);
 }
 
-FASTFLOAT_CONSTEXPR20 inline double
-integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept {
-  double value;
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept {
+  T value;
   if (clinger_fast_path_impl(mantissa, decimal_exponent, false, value))
     return value;
 
   adjusted_mantissa am =
-      compute_float<binary_format<double>>(decimal_exponent, mantissa);
+      compute_float<binary_format<T>>(decimal_exponent, mantissa);
   to_float(false, am, value);
   return value;
 }
 
-FASTFLOAT_CONSTEXPR20 inline double
-integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept {
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept {
   const bool is_negative = mantissa < 0;
   const uint64_t m = static_cast<uint64_t>(is_negative ? -mantissa : mantissa);
 
-  double value;
+  T value;
   if (clinger_fast_path_impl(m, decimal_exponent, is_negative, value))
     return value;
 
-  adjusted_mantissa am =
-      compute_float<binary_format<double>>(decimal_exponent, m);
+  adjusted_mantissa am = compute_float<binary_format<T>>(decimal_exponent, m);
   to_float(is_negative, am, value);
   return value;
 }
 
+FASTFLOAT_CONSTEXPR20 inline double
+integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<double>(mantissa, decimal_exponent);
+}
+
+FASTFLOAT_CONSTEXPR20 inline double
+integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<double>(mantissa, decimal_exponent);
+}
+
 // the following overloads are here to avoid surprising ambiguity for int,
 // unsigned, etc.
+template <typename T, typename Int>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value &&
+                                std::is_integral<Int>::value &&
+                                !std::is_signed<Int>::value,
+                            T>::type
+    integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<T>(static_cast<uint64_t>(mantissa),
+                                decimal_exponent);
+}
+
+template <typename T, typename Int>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value &&
+                                std::is_integral<Int>::value &&
+                                std::is_signed<Int>::value,
+                            T>::type
+    integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<T>(static_cast<int64_t>(mantissa),
+                                decimal_exponent);
+}
+
 template <typename Int>
-FASTFLOAT_CONSTEXPR20 inline typename std::enable_if<
+FASTFLOAT_CONSTEXPR20 typename std::enable_if<
     std::is_integral<Int>::value && !std::is_signed<Int>::value, double>::type
 integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
   return integer_times_pow10(static_cast<uint64_t>(mantissa), decimal_exponent);
 }
 
 template <typename Int>
-FASTFLOAT_CONSTEXPR20 inline typename std::enable_if<
+FASTFLOAT_CONSTEXPR20 typename std::enable_if<
     std::is_integral<Int>::value && std::is_signed<Int>::value, double>::type
 integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
   return integer_times_pow10(static_cast<int64_t>(mantissa), decimal_exponent);