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If s is a null pointer and n is zero, this function has no effect.
Otherwise, the effect is implementation-defined: some implementations do nothing, while some implementations clear the std::string member currently used as the buffer and begin using the user-supplied character array of size n, whose first element is pointed to by s, as the buffer and the input/output character sequence.
This function is protected virtual, it may only be called through pubsetbuf() or from member functions of a user-defined class derived from std::basic_stringbuf.
Parameters
| s | - | pointer to the first byte in the user-provided buffer or null |
| n | - | the number of bytes in the user-provided buffer or zero |
Return value
this.
Notes
The deprecated stream buffer std::strstreambuf or the boost.IOStreams device boost::basic_array may be used to implement I/O buffering over a user-provided char array in portable manner.
Example
Test for the stringstream's setbuf functionality.
1 2 3 4 5 6 7 8 9 10 11 | #include <iostream>#include <sstream> int main(){ std::ostringstream ss; char c[1024] = {}; ss.rdbuf()->pubsetbuf(c, 1024); ss << 3.14 << '\n'; std::cout << c << '\n';} |
Output:
1 2 | 3.14 (on GNU g++/libstdc++ and SunPro C++/roguewave)<nothing> (on MS Visual Studio 2010, SunPro C++/stlport4, CLang++/libc++) |
See also
invokes setbuf() (public member function of std::basic_streambuf) |
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