std::ratio_less - cppreference.com

From cppreference.com


`template< class R1, class R2 > struct ratio_less : std::integral_constant<bool, /* see below */> { };`		(since C++11)

If the ratio R1 is less than the ratio R2, provides the member constant value equal true. Otherwise, value is false.

Helper variable template

`template< class R1, class R2 > constexpr bool ratio_less_v = ratio_less<R1, R2>::value;`		(since C++17)

Inherited from std::integral_constant

Member constants

true if R1::num * R2::den < R2::num * R1::den, or equivalent expression that avoids overflow, false otherwise
(public static member constant)

Member functions

	converts the object to `bool`, returns `value` (public member function)
	returns `value` (public member function)

Member types

Type	Definition
`value_type`	`bool`
`type`	`std::integral_constant<bool, value>`

Example

#include <iostream>
#include <ratio>
 
int main()
{
    using x = std::ratio<69, 90>;
    using y = std::ratio<70, 90>;

    if constexpr (std::ratio_less_v<x, y>)
        std::cout << x::num << '/' << x::den << " < "
                  << y::num << '/' << y::den << '\n';
}