common/alnumbers.h

   1 #ifndef COMMON_ALNUMBERS_H
   2 #define COMMON_ALNUMBERS_H
   3
   4 #include <type_traits>
   5
   6 namespace al::numbers {
   7
   8 namespace detail_ {
   9     template<typename T>
  10     using as_fp = std::enable_if_t<std::is_floating_point<T>::value, T>;
  11 } // detail_
  12
  13 template<typename T>
  14 inline constexpr auto pi_v = detail_::as_fp<T>(3.141592653589793238462643383279502884L);
  15
  16 template<typename T>
  17 inline constexpr auto inv_pi_v = detail_::as_fp<T>(0.318309886183790671537767526745028724L);
  18
  19 template<typename T>
  20 inline constexpr auto sqrt2_v = detail_::as_fp<T>(1.414213562373095048801688724209698079L);
  21
  22 template<typename T>
  23 inline constexpr auto sqrt3_v = detail_::as_fp<T>(1.732050807568877293527446341505872367L);
  24
  25 inline constexpr auto pi = pi_v<double>;
  26 inline constexpr auto inv_pi = inv_pi_v<double>;
  27 inline constexpr auto sqrt2 = sqrt2_v<double>;
  28 inline constexpr auto sqrt3 = sqrt3_v<double>;
  29
  30 } // namespace al::numbers
  31
  32 #endif /* COMMON_ALNUMBERS_H */