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Difference between revisions of "cpp/numeric/ratio/ratio less equal"

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< cpp‎ | numeric‎ | ratio
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{{cpp/title | ratio_less_equal}}
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{{cpp/title|ratio_less_equal}}
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{{cpp/numeric/ratio/sidebar}}
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{{cpp/numeric/ratio/navbar}}
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{{ddcl list begin}}
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{{ddcl|header=ratio|since=c++11|1=
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{{ddcl list header | ratio}}
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{{ddcl list item | 1=
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template< class R1, class R2 >
 
template< class R1, class R2 >
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struct ratio_less_equal : std::integral_constant;
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struct ratio_less_equal : std::integral_constant<bool, /* see below */> { };
 
}}
 
}}
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{{ddcl list end}}
 
  
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If the ratio {{tt|R1}} is less than or equal to the ratio {{tt|R2}}, provides the member constant {{tt|value}} equal {{cpp|true}}. Otherwise, {{tt|value}} is {{cpp|false}}.
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If the ratio {{tt|R1}} is less than or equal to the ratio {{tt|R2}}, provides the member constant {{c|value}} equal {{c|true}}. Otherwise, {{c|value}} is {{c|false}}.
  
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{{cpp/types/integral_constant/inherit | {{cpp|1=R1::num * R2::den <= R2::num * R1::den}}, or equivalent expression that avoids overflow }}
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===Helper variable template===
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{{ddcl|since=c++17|1=
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template< class R1, class R2 >
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constexpr bool ratio_less_equal_v = ratio_less_equal<R1, R2>::value;
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}}
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{{cpp/types/integral_constant/inherit|{{c|1=R1::num * R2::den <= R2::num * R1::den}}, or equivalent expression that avoids overflow}}
  
 
===Example===
 
===Example===
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{{example cpp |
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{{example
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| code=
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|code=
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| output=
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#include <iostream>
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#include <ratio>
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int main()
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{
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    static_assert(std::ratio_less_equal<std::ratio<1, 2>, std::ratio<3, 4>>::value,
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                  "1/2 <= 3/4");
 +
 
 +
    if (std::ratio_less_equal<std::ratio<10,11>, std::ratio<11,12>>::value)
 +
        std::cout << "10/11 <= 11/12" "\n";
 +
 
 +
    static_assert(std::ratio_less_equal_v<std::ratio<10, 11>, std::ratio<11, 12>>);
 +
 
 +
    if constexpr (std::ratio_less_equal_v<std::ratio<10, 11>, std::ratio<11, 12>>)
 +
        std::cout << "11/12 <= 12/13" "\n";
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}
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|output=
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10/11 <= 11/12
 +
11/12 <= 12/13
 
}}
 
}}
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 +
===See also===
 +
{{dsc begin}}
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{{dsc inc|cpp/numeric/ratio/dsc ratio_equal}}
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{{dsc inc|cpp/numeric/ratio/dsc ratio_not_equal}}
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{{dsc end}}
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 +
{{langlinks|de|es|fr|it|ja|pt|ru|zh}}

Latest revision as of 14:49, 24 September 2024

 
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Compile-time rational arithmetic
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ratio_less_equal
(C++11)
(C++11)
(C++11)
 
Defined in header <ratio>
template< class R1, class R2 >
struct ratio_less_equal : std::integral_constant<bool, /* see below */> { };
 (since C++11)

If the ratio R1 is less than or equal to the ratio R2, provides the member constant value equal true. Otherwise, value is false.

Contents

[edit] Helper variable template

template< class R1, class R2 >
constexpr bool ratio_less_equal_v = ratio_less_equal<R1, R2>::value;
 (since C++17)
[edit]

Inherited from std::integral_constant

Member constants

value
[static]
 true if R1::num * R2::den <= R2::num * R1::den, or equivalent expression that avoids overflow, 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] Example

Run this code
#include <iostream>
#include <ratio>
 
int main()
{
    static_assert(std::ratio_less_equal<std::ratio<1, 2>, std::ratio<3, 4>>::value,
                  "1/2 <= 3/4");
 
    if (std::ratio_less_equal<std::ratio<10,11>, std::ratio<11,12>>::value)
        std::cout << "10/11 <= 11/12" "\n";
 
    static_assert(std::ratio_less_equal_v<std::ratio<10, 11>, std::ratio<11, 12>>);
 
    if constexpr (std::ratio_less_equal_v<std::ratio<10, 11>, std::ratio<11, 12>>)
        std::cout << "11/12 <= 12/13" "\n";
}

Output: 

10/11 <= 11/12
11/12 <= 12/13

[edit] See also

(C++11)
 compares two ratio objects for equality at compile-time
(class template) [edit]
(C++11)
 compares two ratio objects for inequality at compile-time
(class template) [edit]
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