E.V.E  0.1-beta

◆ is_equal

eve::is_equal = {}
inlineconstexpr

Callable object computing the equality predicate.

Required header: #include <eve/function/is_equal.hpp>

Members Functions

Member Effect
operator() the equality predicate
operator[] Construct a conditional version of current function object

template< value T, value U > auto operator()( T x, U y ) const noexcept requires compatible< T, U >;

Parameters

x, y: values.

Return value

Returns the logical value containing the elementwise equality test result between x and y. The infix notation x == y can also be used.

The result type is the common compatible type of the two parameters.

Warning
Although the infix notation with == is supported, the == operator on standard scalar types is the original one and so returns bool result, not logical.
auto operator[]( conditional_expression auto cond ) const noexcept;

Higher-order function generating a masked version of eve::is_equal

Parameters

cond : conditional expression

Return value

A Callable object so that the expression is_equal[cond](x, y) is equivalent to if_else(cond,is_equal(x, y),false(as(is_equal(x, y))))

— //! —

Supported decorators

  • eve::numeric

    Required header: #include <eve/function/numeric/is_equal.hpp>

    The expression numeric(is_equal)(x,y) considers that Nan values are equal.

  • almost

    Required header: #include <eve/function/fuzzy/is_equal.hpp>

    The expression almost(is_equal)(x, y, t) where x and y must be floating point values, evals to true if and only if x is almost equal to y. This means that:

    • if t is a floating_value then the relative error of confusing is x and y is less than t \((|x-y| \le t \max(|x|, |y|))\).
    • if t is a positive integral_value then there are not more than t values of the type of x representable in the interval \([x,y[\).
    • if t is omitted then the tolerance t is taken to 3 times the machine \(\epsilon\) in the x type (3*eps(as(x))).

Example

See it live on Compiler Explorer

#include <eve/function/is_equal.hpp>
#include <eve/wide.hpp>
#include <iostream>
int main()
{
wide_ft pf = {0.0f, 1.0f, -1.0f, -2.0f};
wide_ft qf = {1.0f, -1.0f, 0.0f, -2.0f};
std::cout << "---- simd" << '\n'
<< "<- pf = " << pf << '\n'
<< "<- qf = " << qf << '\n'
<< "-> is_equal(pf, qf) = " << eve::is_equal(pf, qf) << '\n';
float xf = 1.0f;
float yf = 2.0f;
std::cout << "---- scalar" << '\n'
<< "<- xf = " << xf << '\n'
<< "<- yf = " << yf << '\n'
<< "-> is_equal(xf, yf) = " << eve::is_equal(xf, yf) << '\n';
return 0;
}
constexpr callable_is_equal_ is_equal
Callable object computing the equality predicate.
Definition: is_equal.hpp:98
Wrapper for SIMD registers.
Definition: wide.hpp:65