std::basic_ios<CharT,Traits>::rdbuf
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| std::basic_streambuf<CharT, Traits>* rdbuf() const; |
(1) | |
| std::basic_streambuf<CharT, Traits>* rdbuf( std::basic_streambuf<CharT, Traits>* sb ); |
(2) | |
Manages the associated stream buffer.
1) Returns the associated stream buffer. If there is no associated stream buffer, returns a null pointer.
2) Sets the associated stream buffer to
sb. The error state is cleared by calling clear(). Returns the associated stream buffer before the operation. If there is no associated stream buffer, returns a null pointer.Parameters
| sb | - | stream buffer to associate to |
Return value
The associated stream buffer, or a null pointer if there was no associated stream buffer.
Exceptions
May throw implementation-defined exceptions.
Example
Run this code
#include <iostream> #include <sstream> int main() { std::ostringstream local; auto cout_buff = std::cout.rdbuf(); // save pointer to std::cout buffer std::cout.rdbuf(local.rdbuf()); // substitute internal std::cout buffer with // buffer of 'local' object // now std::cout work with 'local' buffer // you don't see this message std::cout << "some message"; // go back to old buffer std::cout.rdbuf(cout_buff); // you will see this message std::cout << "back to default buffer\n"; // print 'local' content std::cout << "local content: " << local.str() << "\n"; }
Output:
back to default buffer local content: some message
See also
replaces the rdbuf without clearing its error state (protected member function) |