is_less

eve::is_less = functor<is_less_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto is_less(value auto x, value auto y) noexcept;                          // 1
 
   // Lanes masking
   constexpr auto is_less[conditional_expr auto c](value auto x, value auto y) noexcept; // 2
   constexpr auto is_less[logical_value auto m](value auto x, value auto y) noexcept;    // 2
 
   // Semantic option
   constexpr auto is_less[definitely](/*any of the above overloads*/)          noexcept; // 3
   constexpr auto is_less[definitely = tol](/*any of the above overloads*/)    noexcept; // 3
}

Parameters

• x, y: arguments.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.
• tol: scalar value tolerance.

Return value

1. The call eve::is_less(x,y) is semantically equivalent to x < y:
2. The operation is performed conditionnaly.
3. The expression is_greater[definitely = tol](x, y) where x and y must be floating point values, evaluates to true if and only if x is definitely greater than y. This means that:
   • if tol is a floating value then \(x < y - \mbox{tol}\cdot \max(|x|, |y|)\)
   • if tol is a positive integral value then \(x < \mbox{prev}(y, \mbox{tol})\);
   • if tol is omitted then the tolerance tol default to 3*eps(as(x)).

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 wf1{0.0, -4.0, 1.0, -1.0, 2.0, -2.0, 3.0, -3.0};
  eve::wide wi0{0, 1, 2, 3, -1, -2, -3, -4};
  eve::wide wi1{0, -4, 1, -1, 2, -2, 3, -3};
  eve::wide wu0{0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u};
  eve::wide wu1{7u, 6u, 5u, 4u, 3u, 2u, 1u, 0u};
 
  std::cout << "<- wf0                               = " << wf0 << "\n";
  std::cout << "<- wf1                               = " << wf1 << "\n";
  std::cout << "<- wi0                               = " << wi0 << "\n";
  std::cout << "<- wi1                               = " << wi1 << "\n";
  std::cout << "<- wu0                               = " << wu0 << "\n";
  std::cout << "<- wu1                               = " << wu1 << "\n";
                                                     
  std::cout << "-> is_less(wf0, wf1)                 = " << eve::is_less(wf0, wf1) << "\n";
  std::cout << "-> is_less[ignore_last(2)](wf0, wf1) = " << eve::is_less[eve::ignore_last(2)](wf0, wf1) << "\n";
  std::cout << "-> is_less[wf0 != 0](wf0, wf1)       = " << eve::is_less[wf0 != 0](wf0, wf1) << "\n";
  std::cout << "-> is_less[definitely](wf0, wf1)     = " << eve::is_less[eve::definitely](wf0, wf1) << "\n";
  std::cout << "-> is_less(wu0, wu1)                 = " << eve::is_less(wu0, wu1) << "\n";
  std::cout << "-> is_less[ignore_last(2)](wu0, wu1) = " << eve::is_less[eve::ignore_last(2)](wu0, wu1) << "\n";
  std::cout << "-> is_less[wu0 != 0](wu0, wu1)       = " << eve::is_less[wu0 != 0](wu0, wu1) << "\n";
  std::cout << "-> is_less(wi0, wi1)                 = " << eve::is_less(wi0, wi1) << "\n";
  std::cout << "-> is_less[ignore_last(2)](wi0, wi1) = " << eve::is_less[eve::ignore_last(2)](wi0, wi1) << "\n";
  std::cout << "-> is_less[wi0 != 0](wi0, wi1)       = " << eve::is_less[wi0 != 0](wi0, wi1) << "\n";
}