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std::literals::chrono_literals::operator""h

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< cpp‎ | chrono
Revision as of 07:25, 24 November 2013 by Cubbi (Talk | contribs)

 
 
 
 
 
Defined in header <chrono>
constexpr chrono::hours operator "" h(unsigned long long hrs);
(1) (since C++14)
constexpr chrono::duration</*unspecified*/, std::ratio<3600,1>>
                        operator "" h(long double hrs);
(2) (since C++14)

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

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

Contents

Parameters

hrs - the number of hours

Return value

The std::chrono::duration literal.

Possible implementation

constexpr std::chrono::hours operator ""h(unsigned long long h)
{
    return std::chrono::hours(h);
}
constexpr std::chrono::duration<long double, ratio<3600,1>> operator ""h(long double h)
{
    return std::chrono::duration<long double, std::ratio<3600,1>>(h);
}

Notes

These operators are declared in the namespace std::literals::chrono_literals, where both literals and chrono_literals are inline namespaces.

Example

#include <iostream>
#include <chrono>
 
int main()
{
    using namespace std::literals::chrono_literals;
    auto day = 24h;
    auto halfhour = 0.5h;
    std::cout << "one day is " << day.count() << " hours\n"
              << "half an hour is " << halfhour.count() << " hours\n";
}

Output:

one day is 24 hours
half an hour is 0.5 hours

See also

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