std::basic_ios<CharT,Traits>::rdbuf
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basic_ios::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.
[edit] Parameters
sb
-
Stream buffer to associate to.
[edit] Return value
The associated stream buffer, or a null pointer if there was no associated stream buffer.
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] 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