std::ostream_iterator::operator=

From cppreference.com
ostream_iterator& operator=( const T& value );

Inserts value into the associated stream, then inserts the delimiter, if one was specified at construction time.

If out_stream is a pointer to the associated std::basic_ostream and delim is the delimiter specified at the construction of this object, then the effect is equivalent to

*out_stream << value;
if(delim != 0)
    *out_stream << delim;
return *this;

Parameters

value - the object to insert

Return value

*this

Notes

T can be any class with a user-defined operator<<

Example

#include <iostream>
#include <iterator>
 
int main()
{
    std::ostream_iterator<int> i1(std::cout, ", ");
    *i1++ = 1; // usual form, used by standard algorithms
    *++i1 = 2;
    i1 = 3; // neither * nor ++ are necessary
    std::ostream_iterator<double> i2(std::cout);
    i2 = 3.14;
}

Output:

1, 2, 3, 3.14