std::ratio_equal

C++

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Technical Specifications

Numerics library

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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_equal : std::integral_constant;		(since C++11)

If the ratios R1 and R2 are equal, provides the member constant value equal true. Otherwise, value is false.

Helper variable template

template< class R1, class R2 > inline constexpr bool ratio_equal_v = ratio_equal<R1, R2>::value;		(since C++17)

Inherited from std::integral_constant

Member constants

value [static]

true if R1::num == R2::num && R1::den == R2::den , 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>

Possible implementation

template< class R1, class R2 > struct ratio_equal : public std::integral_constant < bool, R1::num == R2::num && R1::den == R2::den > {};

Example

Run this code

#include <iostream>
#include <ratio>

int main()
{
    if(std::ratio_equal<std::ratio<2,3>, std::ratio<4,6>>::value) {
        std::cout << "2/3 == 4/6\n";
    } else {
        std::cout << "2/3!= 4/6\n";
    }
}

Output:

2/3 == 4/6