NAME¶

std::ostreambuf_iterator::ostreambuf_iterator - std::ostreambuf_iterator::ostreambuf_iterator

Synopsis¶

ostreambuf_iterator( streambuf_type* buffer ) (until C++11)
throw();
ostreambuf_iterator( streambuf_type* buffer ) (since C++11)
noexcept; (1)
ostreambuf_iterator( ostream_type& stream ) (until C++11)
throw(); (2)
ostreambuf_iterator( ostream_type& stream ) (since C++11)
noexcept;

1) Constructs the iterator with the private streambuf_type* member set to buffer and
the failed() flag set to false. The behavior is undefined if buffer is a null
pointer.
2) Same as ostreambuf_iterator(stream.rdbuf()).

Parameters¶

stream - the output stream whose rdbuf() will be accessed by this iterator
buffer - the output stream buffer to be accessed by this iterator

Example¶

// Run this code

#include <fstream>
#include <iostream>
#include <iterator>

int main()
{
const char* file = "test.txt";
{
std::basic_filebuf<char> f;
f.open(file, std::ios::out);
std::ostreambuf_iterator<char> out1(&f);
*out1 = 'a'; // writes to file via iterator
}

// read back from the file
char a;
std::cout << ((std::ifstream{file} >> a), a) << std::endl;

std::ostreambuf_iterator<wchar_t> out2{std::wcout};
*out2 = L'b';
}

Output:¶

a
b

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 112 C++98 the requirement "the argument cannot applies to overload
be null" was applied to overload (2) (1) instead
P2325R3 C++20 default constructor was provided as C++20 removed along with
iterators must be default_initializable the requirement