std::ratio_less

 

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Compile-time rational arithmetic
Compile-time integer sequences
integer_sequence (C++14)

 

Compile time rational arithmetic

ratio (C++11)

Arithmetic

ratio_add (C++11)

ratio_subtract (C++11)

ratio_multiply (C++11)

ratio_divide (C++11)

Comparison

ratio_equal (C++11)

ratio_not_equal (C++11)

ratio_less (C++11)

ratio_less_equal (C++11)

ratio_greater (C++11)

ratio_greater_equal (C++11)

 

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

Run this code

#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

ratio_greater (C++11)

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