Difference between revisions of "cpp/numeric/ratio/ratio equal"
From cppreference.com
m (~) |
m (→Example: modernized) |
||
| Line 35: | Line 35: | ||
#include <iostream> | #include <iostream> | ||
#include <ratio> | #include <ratio> | ||
| − | + | ||
int main() | int main() | ||
{ | { | ||
| − | + | std::<std::ratio<2,3>, std::ratio<4,6>> | |
| − | + | ) | |
| − | + | std::cout << "2/3 ==" : << " 4/6\n"; | |
| − | + | ||
| − | + | ||
} | } | ||
| output= | | output= | ||
Revision as of 13:22, 16 February 2022
| 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.
Contents |
Helper variable template
| template< class R1, class R2 > inline constexpr bool ratio_equal_v = ratio_equal<R1, R2>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
true if R1::num == R2::num && R1::den == R2::den , false otherwise (public static member constant) |
Member functions
| operator bool |
converts the object to bool, returns value (public member function) |
| operator() (C++14) |
returns value (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>>; static_assert( equ ); std::cout << "2/3 " << (equ ? "==" : "!=") << " 4/6\n"; }
Output:
2/3 == 4/6
