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std::islessgreater - cppreference.com

From cppreference.com

Defined in header <cmath>

(1)

bool islessgreater( float x, float y ); bool islessgreater( double x, double y ); bool islessgreater( long double x, long double y );

 (since C++11)
(until C++23)

constexpr bool islessgreater( /* floating-point-type */ x, {{#pad:|13}} /* floating-point-type */ y );

 (since C++23)

Defined in header <cmath>

template< class Arithmetic1, class Arithmetic2 > bool islessgreater( Arithmetic1 x, Arithmetic2 y );

 (A) (since C++11)
(constexpr since C++23)

1) Determines if the floating point number x is less than or greater than the floating-point number y, without setting floating-point exceptions. The library provides overloads for all cv-unqualified floating-point types as the type of the parameters x and y.(since C++23)

A) Additional overloads are provided for all other combinations of arithmetic types.

Parameters

x, y - floating-point or integer values

Return value

true if x < y || x > y, false otherwise.

Notes

The built-in operator< and operator> for floating-point numbers may raise FE_INVALID if one or both of the arguments is NaN. This function is a "quiet" version of the expression x < y || x > y.

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their first argument num1 and second argument num2:

  • If num1 or num2 has type long double, then std::islessgreater(num1, num2) has the same effect as std::islessgreater(static_cast<long double>(num1),
    {{#pad:|19}}static_cast<long double>(num2))    .
  • Otherwise, if num1 and/or num2 has type double or an integer type, then std::islessgreater(num1, num2) has the same effect as std::islessgreater(static_cast<double>(num1),
    {{#pad:|19}}static_cast<double>(num2))    .
  • Otherwise, if num1 or num2 has type float, then std::islessgreater(num1, num2) has the same effect as std::islessgreater(static_cast<float>(num1),
    {{#pad:|19}}static_cast<float>(num2))    .
 (until C++23)

If num1 and num2 have arithmetic types, then std::islessgreater(num1, num2) has the same effect as std::islessgreater(static_cast</*common-floating-point-type*/>(num1),
{{#pad:|19}}static_cast</*common-floating-point-type*/>(num2)), where /*common-floating-point-type*/ is the floating-point type with the greatest floating-point conversion rank and greatest floating-point conversion subrank between the types of num1 and num2, arguments of integer type are considered to have the same floating-point conversion rank as double.

If no such floating-point type with the greatest rank and subrank exists, then overload resolution does not result in a usable candidate from the overloads provided.

(since C++23)

See also

checks if the first floating-point argument is less than the second
(function) [edit]
checks if the first floating-point argument is greater than the second
(function) [edit]