dec

eve::dec = {}

inlineconstexpr

return the input decremented by 1.

Defined in Header

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   template< eve::value T >
   T dec(T x) noexcept;
}

Parameters

• x : real or complex argument.

Return value

The value of x - 1 is returned.

Example

#include <eve/module/core.hpp>
#include <eve/wide.hpp>
#include <iostream>
 
using wide_ft = eve::wide<float, eve::fixed<4>>;
 
int main()
{
  wide_ft pf = {0.0f, 1.0f, -1.0f, -2.0f};
 
  std::cout << "---- simd" << '\n'
            << "<- pf           = " << pf << '\n'
            << "-> dec(pf)       = " << eve::dec(pf) << '\n'; 
 
  float xf = 1.0f;
 
  std::cout << "---- scalar" << '\n'
            << "<- xf           = " << xf << '\n'
            << "-> eve::dec(xf) = " << eve::dec(xf) << '\n';
 
  return 0;
}

Semantic Modifiers

• Masked Call

  The call eve::dec[mask](x, ...) provides a masked version of dec which is equivalent to if_else(mask, dec(x, ...), x)

  Example

  #include <eve/module/core.hpp>
  #include <eve/wide.hpp>
  #include <iostream>
   
  using wide_ft = eve::wide<float, eve::fixed<4>>;
   
  int main()
  {
    wide_ft pf = {0.0f, 1.0f, -1.0f, -2.0f};
   
    std::cout << "---- simd" << '\n'
              << "<- pf           = " << pf << '\n'
              << "-> dec[pf > 0.0f](pf)       = " << eve::dec[pf > 0.0f](pf) << '\n';
    return 0;
  }

• eve::saturated

  The call saturated(dec)(x) computes the saturated decrement of x. The only interest of this behaviour is that for integral type T the call saturated(dec)(Valmin<T>()) returns Valmin<T>().

  Example

  #include <eve/module/core.hpp>
  #include <eve/wide.hpp>
  #include <iostream>
   
  using wide_ft = eve::wide<std::int8_t, eve::fixed<4>>;
   
  int main()
  {
    wide_ft pf = {0, 1, -127, -128};
   
    std::cout << "---- simd" << '\n'
              << "<- pf                 = " << pf << '\n'
              << "-> saturated(dec)(pf) = " << eve::saturated(eve::dec)(pf) << '\n';
    return 0;
  }