Namespaces
Variants
Views
Actions

Difference between revisions of "cpp/numeric/ratio/ratio not equal"

From cppreference.com
< cpp‎ | numeric‎ | ratio
m (Text replace - "{{eq fun cpp" to "{{eq fun")
m (-`inline`: CWG2387; fmt.)
 
(9 intermediate revisions by 6 users not shown)
Line 1: Line 1:
{{cpp/title | ratio_not_equal}}
+
{{cpp/title|ratio_not_equal}}
 
{{cpp/numeric/ratio/navbar}}
 
{{cpp/numeric/ratio/navbar}}
{{ddcl list begin}}
+
{{ddcl|header=ratio|since=c++11|1=
{{ddcl list header | ratio}}
+
{{ddcl list item | 1=
+
 
template< class R1, class R2 >
 
template< class R1, class R2 >
struct ratio_not_equal : std::integral_constant;
+
struct ratio_not_equal : std::integral_constant<bool, /* see below */> { };
 
}}
 
}}
{{ddcl list end}}
 
  
If the ratios R1 and R2 are not equal, provides the member constant {{tt|value}} equal {{c|true}}. Otherwise, {{tt|value}} is {{c|false}}.
+
If the ratios {{tt|R1}} and {{tt|R2}} are not equal, provides the member constant {{c|value}} equal {{c|true}}. Otherwise, {{c|value}} is {{c|false}}.
  
{{cpp/types/integral_constant/inherit | {{c|1=R1::num != R2::num {{!!}} R1::den != R2::den}} }}
+
===Helper variable template===
 +
{{ddcl|since=c++17|1=
 +
template< class R1, class R2 >
 +
constexpr bool ratio_not_equal_v = ratio_not_equal<R1, R2>::value;
 +
}}
 +
 
 +
{{cpp/types/integral_constant/inherit|{{c|1=R1::num != R2::num {{!!}} R1::den != R2::den}}}}
  
 
===Possible implementation===
 
===Possible implementation===
 
{{eq fun
 
{{eq fun
| 1=
+
|1=
 
template< class R1, class R2 >
 
template< class R1, class R2 >
 
struct ratio_not_equal : std::integral_constant <
 
struct ratio_not_equal : std::integral_constant <
Line 25: Line 28:
 
===Example===
 
===Example===
 
{{example
 
{{example
|
+
|code=
| code=
+
#include <iostream>
+
 
#include <ratio>
 
#include <ratio>
  
int main()
+
static_assert(std::ratio_not_equal_v<std::ratio<6, 9>, std::ratio<9, 6>>, "6/9 != 9/6");
{
+
 
    if(std::ratio_not_equal<std::ratio<2,3>, std::ratio<1,3>>::value) {
+
int main() {}
        std::cout << "2/3 != 1/3\n";
+
    } else {
+
        std::cout << "2/3 == 1/3\n";
+
    }
+
}
+
| output=
+
2/3 != 1/3
+
 
}}
 
}}
 +
 +
===See also===
 +
{{dsc begin}}
 +
{{dsc inc|cpp/numeric/ratio/dsc ratio_equal}}
 +
{{dsc end}}
 +
 +
{{langlinks|de|es|fr|it|ja|pt|ru|zh}}

Latest revision as of 14:42, 24 September 2024

 
 
Metaprogramming library
Type traits
Type categories
(C++11)
(C++14)  
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
Type properties
(C++11)
(C++11)
(C++14)
(C++11)
(C++11)(until C++20*)
(C++11)(deprecated in C++20)
(C++11)
Type trait constants
Metafunctions
(C++17)
Supported operations
Relationships and property queries
Type modifications
(C++11)(C++11)(C++11)
Type transformations
(C++11)(deprecated in C++23)
(C++11)(deprecated in C++23)
(C++11)
(C++11)
(C++17)

(C++11)(until C++20*)(C++17)
Compile-time rational arithmetic
Compile-time integer sequences
 
Compile time rational arithmetic
(C++11)
Arithmetic
(C++11)
Comparison
ratio_not_equal
(C++11)
(C++11)
 
Defined in header <ratio>
template< class R1, class R2 >
struct ratio_not_equal : std::integral_constant<bool, /* see below */> { };
(since C++11)

If the ratios R1 and R2 are not equal, provides the member constant value equal true. Otherwise, value is false.

Contents

[edit] Helper variable template

template< class R1, class R2 >
constexpr bool ratio_not_equal_v = ratio_not_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>

[edit] Possible implementation

template< class R1, class R2 >
struct ratio_not_equal : std::integral_constant <
                              bool,
                              !std::ratio_equal<R1, R2>
                         > {};

[edit] Example

#include <ratio>
 
static_assert(std::ratio_not_equal_v<std::ratio<6, 9>, std::ratio<9, 6>>, "6/9 != 9/6");
 
int main() {}

[edit] See also

compares two ratio objects for equality at compile-time
(class template) [edit]