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std::literals::chrono_literals::operator""min

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Revision as of 20:39, 19 March 2014 by Cubbi (Talk | contribs)

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Defined in header <chrono>
constexpr chrono::minutes operator "" min(unsigned long long mins);
(1) (since C++14)
constexpr chrono::duration</*unspecified*/, ratio<60,1>>
                      operator "" min(long double mins);
(2) (since C++14)

Forms a std::chrono::duration literal representing minutes.

1) integer literal, returns exactly std::chrono::minutes(mins)
2) floating-point literal, returns a floating-point duration equivalent to std::chrono::minutes

Contents

[edit] Parameters

minutes - the number of minutes

[edit] Return value

The std::chrono::duration literal.

[edit] Possible implementation

constexpr std::chrono::minutes operator ""min(unsigned long long m)
{
    return std::chrono::minutes(m);
}
constexpr std::chrono::duration<long double,
                                std::ratio<60,1>> operator ""min(long double m)
{
    return std::chrono::duration<long double, ratio<60,1>> (m);
}

[edit] Notes

These operators are declared in the namespace std::literals::chrono_literals, where both literals and chrono_literals are inline namespaces. Access to these operators can be gained with using namespace std::literals and using namespace std::literals::chrono_literals.

In addition, within the namespace std::chrono, the directive using namespace literals::chrono_literals; is provided by the standard library, so that if a programmer uses using namespace std::chrono; to gain access to the duration classes, the duration literal operators become visible as well.

[edit] Example

#include <iostream>
#include <chrono>
 
int main()
{
    using namespace std::literals::chrono_literals;
    auto lesson = 45min;
    auto halfmin = 0.5min;
    std::cout << "one lesson is " << lesson.count() << " minutes\n"
              << "half a minute is " << halfmin.count() << " minutes\n";
}

Output:

one lesson is 45 minutes
half a minute is 0.5 minutes

[edit] See also

constructs new duration
(public member function of std::chrono::duration) [edit]