abs

auto eve::abs = functor<abs_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto abs(value auto x)                          noexcept; // 1
 
   // Lanes masking
   constexpr auto abs[conditional_expr auto c](value auto x) noexcept; // 2
   constexpr auto abs[logical_value auto m](value auto x)    noexcept; // 2
 
   // Semantic options
   constexpr auto abs[saturated](value auto x)               noexcept; // 3
}

Parameters

• x: value.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. The absolute value of x if it is representable.
2. The operation is performed conditionnaly.
3. The saturated absolute value of x. More specifically, for signed integral, abs[saturated](valmin(as<T>{})) returns eve:valmax(as<T>{}))

Note

The absolute value of x is always representable except for The minimum value of integral signed values. In that case, contrarily to the standard, the result is not undefined behaviour, but just incorrect. In this case, eve::abs(valmin) returns valmin.

Warning

abs is also a standard library function name and there possibly exists a C macro version which may be called instead of the EVE version.
To avoid confusion, use the eve::abs notation.

External references

• C++ standard reference
• Wolfram MathWorld
• Wikipedia

Example

// revision 0
#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf0{0.0, 1.0, 2.0, 3.0, -1.0, -2.0, -3.0, -4.0};
  eve::wide wi0{0, 1, 2, 3, -1, -2, -3, -4};
  eve::wide wu0{0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u};
 
  std::cout << "<- wf0                      = " << wf0 << "\n";
  std::cout << "<- wi0                      = " << wi0 << "\n";
  std::cout << "<- wu0                      = " << wu0 << "\n";
 
  std::cout << "-> abs(wf0)                 = " << eve::abs(wf0) << "\n";
  std::cout << "-> abs[ignore_last(2)](wf0) = " << eve::abs[eve::ignore_last(2)](wf0) << "\n";
  std::cout << "-> abs[wf0 != 0](wf0)       = " << eve::abs[wf0 != 0](wf0) << "\n";
  std::cout << "-> abs(wu0)                 = " << eve::abs(wu0) << "\n";
  std::cout << "-> abs[ignore_last(2)](wu0) = " << eve::abs[eve::ignore_last(2)](wu0) << "\n";
  std::cout << "-> abs[wu0 != 0](wu0)       = " << eve::abs[wu0 != 0](wu0) << "\n";
  std::cout << "-> abs[saturated](wu0)      = " << eve::abs[eve::saturated](wu0) << "\n";
  std::cout << "-> abs(wi0)                 = " << eve::abs(wi0) << "\n";
  std::cout << "-> abs[ignore_last(2)](wi0) = " << eve::abs[eve::ignore_last(2)](wi0) << "\n";
  std::cout << "-> abs[wi0 != 0](wi0)       = " << eve::abs[wi0 != 0](wi0) << "\n";
  std::cout << "-> abs[saturated](wi0)      = " << eve::abs[eve::saturated](wi0) << "\n";
}