std::experimental::ostream_joiner<DelimT,CharT,Traits>::operator=

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

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Technical specifications

Symbols index

External libraries

 

Experimental

Technical Specification

Filesystem library (filesystem TS)

Library fundamentals (library fundamentals TS)

Library fundamentals 2 (library fundamentals TS v2)

Library fundamentals 3 (library fundamentals TS v3)

Extensions for parallelism (parallelism TS)

Extensions for parallelism 2 (parallelism TS v2)

Extensions for concurrency (concurrency TS)

Extensions for concurrency 2 (concurrency TS v2)

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Library fundamentals v2

experimental::propagate_const

experimental::not_fn

experimental::observer_ptr

experimental::make_array

experimental::to_array

experimental::ostream_joiner

experimental::gcd

experimental::lcm

experimental::source_location

experimental::randint

detection idiom

uniform container erasure

logical operator type traits

 

std::experimental::ostream_joiner

Member functions

ostream_joiner::ostream_joiner

ostream_joiner::operator=

ostream_joiner::operator*

ostream_joiner::operator++ostream_joiner::operator++(int)

Non-member functions

make_ostream_joiner

 

template< class T > ostream_joiner& operator=( const T& value );	(1)	(library fundamentals TS v2)
ostream_joiner& operator=( const ostream_joiner& other ) = default;	(2)	(library fundamentals TS v2) (implicitly declared)
ostream_joiner& operator=( ostream_joiner&& other ) = default;	(3)	(library fundamentals TS v2) (implicitly declared)

1) First, if the private "first element" flag is false, insert the delimiter delim into the output stream os associated with this iterator as if by os << delim;.

Then, unconditionally sets the "first element" flag to false, and insert value into the output stream as if by os << value;.

Let out_stream, delim, and first_element denote the private stream pointer, delimiter, and "first element" flag members respectively. Then this function is equivalent to

if (!first_element)
    *out_stream << delim;
first_element = false;
*out_stream << value;
return *this;

2,3) Implicitly declared copy/move assignment operator that copy/move assigns the private stream pointer, delimiter, and "first element" flag members.

Parameters

value	-	the object to to be written to the stream
other	-	the ostream_joiner object to be assigned to this object

Return value

*this.

Example

Run this code

#include <experimental/iterator>
#include <iostream>
 
int main()
{
    auto joiner = std::experimental::make_ostream_joiner(std::cout, ", ");
    joiner = "First";
    joiner = "do no harm.";  // prefixes with the delimiter
}

Output:

First, do no harm.