oneotwoeps

auto eve::oneotwoeps = functor<oneotwoeps_t>

inlineconstexpr

Defined in Header

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
  template<eve::floating_value T> constexpr T oneotwoeps(as<T> x) noexcept;
}

Parameters

• x : Type wrapper instance embedding the type of the constant.

Return value

The call eve::oneotwoeps(as<T>()) returns elementwise, the smallest positive value x of the type such that 1+x != x.

• If T is an integral value the elements returned are equal to one.
• If T is a floating value the elements returned are equal to:
  • 4194304 if the elements type is float.
  • 2.2518e+15f if the elements type is double.

Example

// revision 0
#include <eve/module/math.hpp>
#include <iostream>
#include <iomanip>
 
int main()
{
  using wf_t = eve::wide<float>;
  using wd_t = eve::wide<double>;
 
  std::cout << std::setprecision(9);
  std::cout << "-> oneotwoeps(as<float>())          = " << eve::oneotwoeps(eve::as<float>())          << "\n";
  std::cout << "-> oneotwoeps(as<wf_t>())           = " << eve::oneotwoeps(eve::as<wf_t>())           << "\n";
  std::cout << "-> oneotwoeps[lower](as<wf_t>())    = " << eve::oneotwoeps[eve::lower](eve::as<wf_t>()) << "\n";
  std::cout << "-> oneotwoeps[upper](as<wf_t>())    = " << eve::oneotwoeps[eve::upper](eve::as<wf_t>()) << "\n";
 
  std::cout << std::setprecision(17);
  std::cout << "-> oneotwoeps(as<double>())         = " << eve::oneotwoeps(eve::as<double>())         << "\n";
  std::cout << "-> oneotwoeps(as<wd_t>())           = " << eve::oneotwoeps(eve::as<wd_t>())           << "\n";
  std::cout << "-> oneotwoeps[lower](as<wd_t>())    = " << eve::oneotwoeps[eve::lower](eve::as<wd_t>()) << "\n";
  std::cout << "-> oneotwoeps[upper](as<wd_t>())    = " << eve::oneotwoeps[eve::upper](eve::as<wd_t>()) << "\n";
}