NAME¶

std::ratio_divide - std::ratio_divide

Synopsis¶

Defined in header <ratio>
template< class R1, class R2 > (since C++11)
using ratio_divide = /* see below */;

The alias template std::ratio_divide denotes the result of dividing two exact
rational fractions represented by the std::ratio specializations R1 and R2.

The result is a std::ratio specialization std::ratio<U, V>, such that given Num ==
R1::num * R2::den and Denom == R1::den * R2::num (computed without arithmetic
overflow), U is std::ratio<Num, Denom>::num and V is std::ratio<Num, Denom>::den.

Notes¶

If U or V is not representable in std::intmax_t, the program is ill-formed. If Num
or Denom is not representable in std::intmax_t, the program is ill-formed unless the
implementation yields correct values for U and V.

The above definition requires that the result of std::ratio_divide<R1, R2> be
already reduced to lowest terms; for example, std::ratio_divide<std::ratio<1, 12>,
std::ratio<1, 6>> is the same type as std::ratio<1, 2>.

Example¶

// Run this code

#include <iostream>
#include <ratio>

int main()
{
using two_third = std::ratio<2, 3>;
using one_sixth = std::ratio<1, 6>;
using quotient = std::ratio_divide<two_third, one_sixth>;
static_assert(std::ratio_equal_v<quotient, std::ratio<0B100, 0X001>>);
std::cout << "(2/3) / (1/6) = " << quotient::num << '/' << quotient::den << '\n';
}

Output:¶

(2/3) / (1/6) = 4/1

See also¶

ratio_multiply multiplies two ratio objects at compile-time
(C++11) (alias template)