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std::literals::chrono_literals::operator""s(3) | C++ Standard Libary | std::literals::chrono_literals::operator""s(3) |
NAME¶
std::literals::chrono_literals::operator""s - std::literals::chrono_literals::operator""s
Synopsis¶
Defined in header <chrono>
constexpr chrono::seconds operator "" s(unsigned long long secs);
(1) (since C++14)
constexpr chrono::duration</*unspecified*/> operator ""
s(long (2) (since C++14)
double secs);
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>)
2022.07.31 | http://cppreference.com |