mzero

auto eve::mzero = functor<mzero_t>

inlineconstexpr

For integral type there is no difference between eve::zero and eve::mzero, but for floating ones the bit of sign differs.

However, eve::mzero always satisfies the equality predicate with eve::zero and eve::mzero satisfies the predicate is_negative, but not the predicate is_ltz.

Defined in Header

#include <eve/module/core.hpp>

Callable Signatures

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

Parameters

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

Return value

The call eve::mzero(as<T>()) is semantically equivalent to T(-0.0).

Example

#include <eve/module/core.hpp>
#include <eve/wide.hpp>
#include <iostream>
 
using wide_ft = eve::wide<float>;
using wide_it = eve::wide<std::int16_t>;
 
template<typename T>
consteval auto constexpr_mzero() { return eve::mzero(eve::as<T>{}); }
 
int main()
{
  wide_ft wxf;
  wide_it wxi;
 
  std::cout << "---- simd"  << std::endl
            << "-> mzero(as<wide_ft>())  = " << eve::mzero(eve::as<wide_ft>()) << std::endl
            << "-> mzero(as<wide_it>())  = " << eve::mzero(eve::as<wide_it>()) << std::endl
            << "-> mzero(as(wxf))        = " << eve::mzero(eve::as(wxf))       << std::endl
            << "-> mzero(as(wxi))        = " << eve::mzero(eve::as(wxi))       << std::endl;
 
  double       xf;
  std::int16_t xi;
 
  std::cout << "---- scalar" << std::endl
            << "-> mzero(as<float>())         = " << eve::mzero(eve::as(float())) << std::endl
            << "-> mzero(as<std::int16_t>())  = " << eve::mzero(eve::as(std::int16_t())) << std::endl
            << "-> mzero(as<xf))              = " << eve::mzero(eve::as(xf)) << std::endl
            << "-> mzero(as<xi))              = " << eve::mzero(eve::as(xi)) << std::endl;
 
  std::cout << "-> constexpr mzero            = " << constexpr_mzero<float>() << std::endl;
 
  return 0;
}