Setting the internal buffer used by a standard stream (pubsetbuf)

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After some more research on this problem, and scrutiny of my code, I came across a post suggesting the use of a hand-coded std::streambuf class. The idea behind this code is to create a streambuf that initializes its internals to refer to the given buffer. The code is as follows.

#include <streambuf>

template <typename char_type>
struct ostreambuf : public std::basic_streambuf<char_type, std::char_traits<char_type> >
{
    ostreambuf(char_type* buffer, std::streamsize bufferLength)
    {
        // set the "put" pointer the start of the buffer and record it's length.
        setp(buffer, buffer + bufferLength);
    }
};

Now if you look at my original code, you will notice that I didn’t really need a stringstream to begin with. All I really needed was a way to write to an external buffer using the IOStream library and std::ostream is a much better type to address this problem. Incidentally, I suspect this is how the array_sink type from Boost.IOStreams is implemented.

Here is the modified code that uses my ostreambuf type.

#include <ostream>
#include "ostreambuf.h"  // file including ostreambuf struct from above.

void FillBuffer(char* buffer, unsigned int size)
{
    ostreambuf<char> ostreamBuffer(buffer, size);
    std::ostream messageStream(&ostreamBuffer);

    messageStream << "Hello" << std::endl;
    messageStream << "World!" << std::endl;
}

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