std::ratio_equal

 

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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_equal : std::integral_constant<bool, /* see below */> { };		(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 > 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()
{
    constexpr bool equ = std::ratio_equal_v<std::ratio<2,3>,
                                            std::ratio<6,9>>;
    static_assert(equ);
    std::cout << "2/3 " << (equ ? "==" : "!=") << " 6/9\n";
}

Output:

2/3 == 6/9

See also

ratio_not_equal (C++11)

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