std::ratio_divide - cppreference.com (original) (raw)
| | | | | ------------------------------------------------------------------------- | | ------------- | | template< class R1, class R2 > using ratio_divide = /* see below */; | | (since C++11) |
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.
[edit] 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>.
[edit] Example
#include #include 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: