std::literals::chrono_literals::operator""s

 

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std::chrono::duration

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duration::duration duration::operator= duration::count duration::zero duration::min duration::max duration::operator+duration::operator-	duration::operator++duration::operator-- duration::operator+=duration::operator-=duration::operator*=duration::operator/=duration::operator%=
Non-member functions
operator+operator-operator*operator/operator% operator==operator!=operator<operator<=operator>operator>=operator<=> (until C++20)(C++20) operator<< (C++20)	duration_cast floor (C++17) ceil (C++17) round (C++17) abs (C++17) operator""h (C++14) operator""min (C++14) operator""s (C++14) operator""ms (C++14) operator""us (C++14) operator""ns (C++14) from_stream (C++20)
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common_type treat_as_floating_point	duration_values formatter<std::chrono::duration> (C++20)

 

Defined in header <chrono>
constexpr chrono::seconds operator "" s(unsigned long long secs);	(1)	(since C++14)
constexpr chrono::duration</*unspecified*/> operator "" s(long double secs);	(2)	(since C++14)

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

1) integer literal, returns exactly std::chrono::seconds(secs)

2) floating-point literal, returns a floating-point duration equivalent to std::chrono::seconds

Parameters

secs

-

the number of seconds

Return value

The std::chrono::duration literal.

Possible implementation

constexpr std::chrono::seconds operator ""s(unsigned long long s) { return std::chrono::seconds(s); } constexpr std::chrono::duration<long double> operator ""s(long double s) { return std::chrono::duration<long double>(s); }

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, using namespace std::chrono_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 classes in the chrono library, the corresponding literal operators become visible as well.

std::string also defines operator""s, to represent literal objects of type std::string, but it is a string literal: 10s is ten seconds, but "10"s is a two-character string.

Example

Run this code

#include <iostream>
#include <chrono>
 
int main()
{
    using namespace std::chrono_literals;
 
    std::chrono::seconds halfmin = 30s;
    std::cout << "Half a minute is " << halfmin.count() << " seconds.\n"
        "A minute and a second is " << (1min + 1s).count() << " seconds.\n";
 
    std::chrono::duration moment = 0.1s;
    std::cout << "A moment is " << moment.count() << " seconds.\n"
        "And thrice as much is " << (moment + 0.2s).count() << " seconds.\n";
}

Output:

Half a minute is 30 seconds.
A minute and a second is 61 seconds.
A moment is 0.1 seconds.
And thrice as much is 0.3 seconds.

See also

(constructor)

constructs new duration (public member function of std::chrono::duration<Rep,Period>)