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std::ratio_less

Defined in header <ratio> 
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 >
inline constexpr bool ratio_less_v = ratio_less<R1, R2>::value;
 (since C++17)

Inherited from std::integral_constant

Member constants

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

Member functions

operator bool
converts the object to bool, returns value
(public member function)
operator()
(C++14)
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';
}

Output:

23/30 < 7/9

See also

(C++11)
compares two ratio objects for greater than at compile-time
(class template)

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