common/alnumbers.h

   1 #ifndef COMMON_ALNUMBERS_H
   2 #define COMMON_ALNUMBERS_H
   3
   4 #include <utility>
   5
   6 namespace al {
   7
   8 namespace numbers {
   9
  10 namespace detail_ {
  11     template<typename T>
  12     using as_fp = std::enable_if_t<std::is_floating_point<T>::value, T>;
  13 } // detail_
  14
  15 template<typename T>
  16 static constexpr auto pi_v = detail_::as_fp<T>(3.141592653589793238462643383279502884L);
  17
  18 template<typename T>
  19 static constexpr auto inv_pi_v = detail_::as_fp<T>(0.318309886183790671537767526745028724L);
  20
  21 template<typename T>
  22 static constexpr auto sqrt2_v = detail_::as_fp<T>(1.414213562373095048801688724209698079L);
  23
  24 template<typename T>
  25 static constexpr auto sqrt3_v = detail_::as_fp<T>(1.732050807568877293527446341505872367L);
  26
  27 static constexpr auto pi = pi_v<double>;
  28 static constexpr auto inv_pi = inv_pi_v<double>;
  29 static constexpr auto sqrt2 = sqrt2_v<double>;
  30 static constexpr auto sqrt3 = sqrt3_v<double>;
  31
  32 } // namespace numbers
  33
  34 } // namespace al
  35
  36 #endif /* COMMON_ALNUMBERS_H */