ROL_ScalarTraits.hpp

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#pragma once
#ifndef ROL_SCALARTRAITS_HPP
#define ROL_SCALARTRAITS_HPP

#include <limits>
#include <complex>


namespace ROL {

template<typename Real>
struct ScalarTraits_Magnitude {
  using type = Real;
};

template<typename Real>
struct ScalarTraits_Magnitude<std::complex<Real>> {
  using type = Real;
};


template<typename Real>
struct ScalarTraits {

  using magnitudeType = typename ScalarTraits_Magnitude<Real>::type;

  static constexpr Real zero() noexcept { return static_cast<Real>(0.0); }
  static constexpr Real half() noexcept { return static_cast<Real>(0.5); }
  static constexpr Real one()  noexcept { return static_cast<Real>(1.0); }
  static constexpr Real two()  noexcept { return static_cast<Real>(2.0); }

  static constexpr Real eps()  noexcept { 
    return std::numeric_limits<Real>::epsilon(); 
  }

  static constexpr Real rmin()  noexcept {
    return std::numeric_limits<Real>::min(); 
  }

  static constexpr Real rmax()  noexcept {
    return std::numeric_limits<Real>::max(); 
  }

  static constexpr Real two_pi() noexcept {
    return static_cast<Real>( 6.283185307179586476925286766559005768L );
  }

  static constexpr Real pi() noexcept {
    return static_cast<Real>( 3.141592653589793238462643383279502884L );
  }

   static constexpr Real half_pi() noexcept {
     return static_cast<Real>( 1.570796326794896619231321691639751442L );
   }
 
  static constexpr Real quarter_pi() noexcept {
    return static_cast<Real>( 7.85398163397448309615660845819875721e-1L );
  }

  static constexpr Real sqrt_two_pi() noexcept {
    return static_cast<Real>( 2.506628274631000502415765284811045252L );
  }

  static constexpr Real sqrt_pi() noexcept {
    return static_cast<Real>( 1.772453850905516027298167483341145182L );
  }

  static constexpr Real sqrt_half_pi() noexcept {
    return static_cast<Real>( 1.253314137315500251207882642405522626L );
  }

  static constexpr Real sqrt_two() noexcept {
    return static_cast<Real>( 1.414213562373095048801688724209698078L );
  }

};


} // namespace ROL

#endif // ROL_SCALARTRAITS_HPP