std::ratio_subtract
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                    | Defined in header  <ratio> | ||
| template< class R1, class R2 > using ratio_subtract = /* unspecified */; | ||
The template alias std::ratio_subtract denotes the result of subtracting two exact rational fractions represented by the std::ratio instances R1 and R2. The result a std::ratio instance std::ratio<Num, Denom> where Num == R1::num * R2::den - R2::num * R1::den and Denom == R1::den * R2::den.
[edit] Member types
| Member type | Definition | 
| type | std::ratio<num, den> | 
[edit] Member constants
| num [static] | constexpr value of type std::intmax_t equal to sign(Num) * sign(Denom) * abs(Num) / gcd(Num, Denom)(public static member constant) | 
| den [static] | constexpr value of type std::intmax_t equal to abs(Denom) / gcd(Num, Denom)(public static member constant) | 
[edit] Example
Run this code
#include <iostream> #include <ratio> int main() { typedef std::ratio<2, 3> two_third; typedef std::ratio<1, 6> one_sixth; typedef std::ratio_subtract<two_third, one_sixth> diff; std::cout << "2/3 - 1/6 = " << diff::num << '/' << diff::den << '\n'; }
Output:
2/3 - 1/6 = 1/2


