Defined in header <chrono> | ||
---|---|---|
constexpr std::chrono::microseconds operator "" us(unsigned long long us); | (1) | (since C++14) |
constexpr std::chrono::duration</*unspecified*/, std::micro> operator "" us(long double us); | (2) | (since C++14) |
Forms a std::chrono::duration
literal representing microseconds.
std::chrono::microseconds(us)
std::chrono::microseconds
us | - | the number of microseconds |
The std::chrono::duration
literal.
constexpr std::chrono::microseconds operator ""us(unsigned long long us) { return std::chrono::microseconds(us); } constexpr std::chrono::duration<long double, std::micro> operator ""us(long double us) { return std::chrono::duration<long double, std::micro>(us); } |
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 duration classes, the duration literal operators become visible as well.
#include <iostream> #include <chrono> int main() { using namespace std::chrono_literals; auto d1 = 250us; std::chrono::microseconds d2 = 1ms; std::cout << "250us = " << d1.count() << " microseconds\n" << "1ms = " << d2.count() << " microseconds\n"; }
Output:
250us = 250 microseconds 1ms = 1000 microseconds
constructs new duration (public member function of std::chrono::duration ) |
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