is_equal

eve::is_equal = functor<is_equal_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto is_equal(value auto x, value auto y) noexcept;                          // 1
 
   // Lanes masking
   constexpr auto is_equal[conditional_expr auto c](value auto x, value auto y) noexcept; // 2
   constexpr auto is_equal[logical_value auto m](value auto x, value auto y) noexcept;    // 2
 
   // Semantic option
   constexpr auto is_equal[numeric](/*any of the above overloads*/)             noexcept; // 3
   constexpr auto is_equal[almost](/*any of the above overloads*/)              noexcept; // 4
   constexpr auto is_equal[almost = tol](/*any of the above overloads*/)        noexcept; // 4
}

Parameters

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

Return value

1. Returns the logical value containing the elementwise equality test result between x and y. The infix notation x == y can also be used.
2. The operation is performed conditionally.
3. The expression is_equal[numeric](x,y) considers that Nan values are equal.
4. The expression is_equal[almost = tol](x, y) where x and y must be floating point values, evaluates to true if and only if x is almost equal to y. This means that:
   • if tol is a floating value then \(|x - y| \le \mbox{tol}\cdot \max(|x|, |y|)\)
   • if tol is a positive integral value then there are not more than tol values of the type of x representable in the interval \([x, y[\).
   • if tol is omitted then the tolerance tol default to 3*eps(as(x)).

Note

Although the infix notation with == is supported, the == operator on standard scalar types is the original one and so returns bool result, not eve::logical.

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_equal(wf0, wf1)                 = " << eve::is_equal(wf0, wf1) << "\n";
  std::cout << "-> is_equal[ignore_last(2)](wf0, wf1) = " << eve::is_equal[eve::ignore_last(2)](wf0, wf1) << "\n";
  std::cout << "-> is_equal[wf0 != 0](wf0, wf1)       = " << eve::is_equal[wf0 != 0](wf0, wf1) << "\n";
  std::cout << "-> is_equal[numeric](wf0, wf1)        = " << eve::is_equal[eve::numeric](wf0, wf1) << "\n";
  std::cout << "-> is_equal[almost](wf0, wf1)         = " << eve::is_equal[eve::almost](wf0, wf1) << "\n";
  std::cout << "-> is_equal(wu0, wu1)                 = " << eve::is_equal(wu0, wu1) << "\n";
  std::cout << "-> is_equal[ignore_last(2)](wu0, wu1) = " << eve::is_equal[eve::ignore_last(2)](wu0, wu1) << "\n";
  std::cout << "-> is_equal[wu0 != 0](wu0, wu1)       = " << eve::is_equal[wu0 != 0](wu0, wu1) << "\n";
  std::cout << "-> is_equal(wi0, wi1)                 = " << eve::is_equal(wi0, wi1) << "\n";
  std::cout << "-> is_equal[ignore_last(2)](wi0, wi1) = " << eve::is_equal[eve::ignore_last(2)](wi0, wi1) << "\n";
  std::cout << "-> is_equal[wi0 != 0](wi0, wi1)       = " << eve::is_equal[wi0 != 0](wi0, wi1) << "\n";
}