Technical specifications
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)
Concepts (concepts TS)
Ranges (ranges TS)
Reflection (reflection TS)
Mathematical special functions (special functions TR)
Defined in header <experimental/iterator>
template< class DelimT,

          class CharT = char,
          class Traits = std::char_traits<CharT>>

class ostream_joiner;
(library fundamentals TS v2)

std::experimental::ostream_joiner is a single-pass LegacyOutputIterator that writes successive objects into the std::basic_ostream object for which it was constructed, using operator<<, separated by a delimiter. The delimiter is written to the output stream between every two objects that are written. The write operation is performed when the iterator (whether dereferenced or not) is assigned to. Incrementing the ostream_joiner is a no-op.

In a typical implementation, the only data members of ostream_joiner are a pointer to the associated std::basic_ostream, the delimiter, and a bool member that indicates whether the next write is for the first element in the sequence.

Compared to std::ostream_iterator, ostream_joiner prints the delimiter sequence one fewer time, and is not templated on the type of the object to be printed.

Member types

Member type Definition
char_type CharT
traits_type Traits
ostream_type std::basic_ostream<CharT, Traits>
value_type void
difference_type void
pointer void
reference void
iterator_category std::output_iterator_tag

Member functions

constructs a new ostream_joiner
(public member function)
(implicitly declared)
destructs an ostream_joiner
(public member function)
writes a object to the associated output sequence
(public member function)
(public member function)
(public member function)

Non-member functions

creates a ostream_joiner object, deducing the template's type arguments from the function arguments
(function template)


#include <algorithm>
#include <experimental/iterator>
#include <iostream>
#include <iterator>
int main()
    int i[] = {1, 2, 3, 4, 5};
              std::experimental::make_ostream_joiner(std::cout, ", "));


1, 2, 3, 4, 5

See also

output iterator that writes to std::basic_streambuf
(class template)
output iterator that writes to std::basic_ostream
(class template)
input iterator that reads from std::basic_istream
(class template)