template <class R1, class R2> ratio_equal;
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template <class R1, class R2>
struct ratio_equal : integral_constant<bool, R1::num==R2::num && R1::den==R2::den> {};| member constant | definition |
|---|---|
| value | either true or false |
| member type | definition |
|---|---|
| value_type | bool |
| type | either true_type or false_type |
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// ratio_equal example
#include <iostream>
#include <ratio>
int main ()
{
typedef std::ratio<1,2> one_half;
typedef std::ratio<2,4> two_fourths;
std::cout << "1/2 == 2/4 ? " << std::boolalpha;
std::cout << std::ratio_equal<one_half,two_fourths>::value << std::endl;
return 0;
}1/2 == 2/4 ? true