std::chrono::operator<< (std::chrono::duration)
| Defined in header <chrono>
|
||
| template< class CharT, |
(since C++20) | |
Inserts a textual representation of d into os.
Behaves as if it was implemented as
std::basic_ostringstream<CharT, Traits> s; s.flags(os.flags()); s.imbue(os.getloc()); s.precision(os.precision()); s << d.count() << units_suffix; // see below return os << s.str();
In other words, the stream flags, locale, and precision are determined by the stream, but any padding are determined using the entire output string.
The units_suffix is determined based on Period::type according to the following table.
Period::type
|
Suffix |
| std::atto | as
|
| std::femto | fs
|
| std::pico | ps
|
| std::nano | ns
|
| std::micro | µs (U+00B5) or us, it is implementation-defined which one is used
|
| std::milli | ms
|
| std::centi | cs
|
| std::deci | ds
|
| std::ratio<1> | s
|
| std::deca | das
|
| std::hecto | hs
|
| std::kilo | ks
|
| std::mega | Ms
|
| std::giga | Gs
|
| std::tera | Ts
|
| std::peta | Ps
|
| std::exa | Es
|
| std::ratio<60> | min
|
| std::ratio<3600> | h
|
| std::ratio<86400> | d
|
| None of the above, and Period::type::den == 1 | [num]s
|
| None of the above | [num/den]s
|
For the last two rows of the table, num and den in the suffix are Period::type::num and Period::type::den formatted as a decimal number with no leading zeroes, respectively.
Return value
A reference to the stream, i.e., os.
Example
This example shows the output of std::chrono::operator<< when given a duration:
#include <chrono> #include <iostream> using namespace std::chrono_literals; int main() { constexpr auto duration = 123ms; std::cout << duration << '\n'; }
Output:
123ms
See also
| (C++20) |
stores formatted representation of the arguments in a new string (function template) |
formatting support for duration (class template specialization) | |
| performs stream input and output on strings (function template) | |
| (C++11) |
converts an integral or floating-point value to string (function) |
| (C++11) |
converts an integral or floating-point value to wstring (function) |