std::literals::chrono_literals::operator""us

 

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Date and time library

Time point time_point (C++11) clock_time_conversion (C++20)   clock_cast (C++20) Duration duration (C++11) Clocks system_clock (C++11) steady_clock (C++11) is_clock (C++20) utc_clock (C++20) tai_clock (C++20) high_resolution_clock (C++11) gps_clock (C++20) file_clock (C++20) local_t (C++20) Time of day is_amis_pm (C++20)(C++20) make12make24 (C++20)(C++20) hh_mm_ss (C++20)

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std::chrono::duration

Member functions
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)
Helper classes
common_type treat_as_floating_point      duration_values	formatter<std::chrono::duration> (C++20) hash<std::chrono::duration> (C++26)

 

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.

1) Integer literal, returns exactly std::chrono::microseconds(us).

2) Floating-point literal, returns a floating-point duration equivalent to std::chrono::microseconds.

Parameters

us

-

the number of microseconds

Return value

The std::chrono::duration literal.

Possible implementation

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); }

Notes

This operator is declared in the namespace std::literals::chrono_literals, where both literals and chrono_literals are inline namespaces. Access to this operator can be gained with:

• using namespace std::literals,
• using namespace std::chrono_literals, or
• 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.

Example

Run this code

#include <chrono>
#include <iostream>

int main()
{
    using namespace std::chrono_literals;
    auto d1 = 250us;
    std::chrono::microseconds d2 = 1ms;
    std::cout << d1 << " = " << d1.count() << " microseconds\n"
              << 1ms << " = " << d2.count() << " microseconds\n";
}

Output:

250us = 250 microseconds
1ms = 1000 microseconds

See also

(constructor)

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