NAME¶

std::ratio_equal - std::ratio_equal

Synopsis¶

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

Inherited from std::integral_constant

Member constants¶

value true if R1::num == R2::num && R1::den == R2::den , false otherwise
[static] (public static member constant)

Member functions¶

operator bool converts the object to bool, returns value
(public member function)
operator() returns value
(C++14) (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<4,6>>;

std::cout << "2/3 " << (equ ? "==" : "!=") << " 4/6\n";
}

Output:¶

2/3 == 4/6

See also¶