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

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Utilities library

Type support (basic types, RTTI, type traits)

Dynamic memory management

Error handling

Program utilities

Variadic functions

Date and time

Function objects

initializer_list (C++11)

bitset

hash (C++11)

Relational operators

rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=

Pairs and tuples

pair

tuple (C++11)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

Swap, forward and move

swap

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

declval (C++11)

 

Date and time utilities

time_point (C++11)

duration (C++11)

system_clock (C++11)

steady_clock (C++11)

high_resolution_clock (C++11)

C-style date and time

 

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>=	common_type duration_cast operator""h (C++14) operator""min (C++14) operator""s (C++14) operator""ms (C++14) operator""us (C++14) operator""ns (C++14)
Helper classes
treat_as_floating_point
duration_values

 

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

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 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.

Example

Run this code

#include <iostream>
#include <chrono>
 
int main()
{
    using namespace std::literals::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

See also

(constructor)

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