A stream buffer that capitalizes every word of a sentence.

gistfile1.cpp

#include <iostream>

class stream_buffer : public std::streambuf
{
public:
    stream_buffer(std::ostream& os)
        : whitespace(true),
          ctype(std::use_facet<std::ctype<char>>(getloc())),
          m_sbuf(os.rdbuf())
    { }

    int_type overflow(int_type c)
    {
        int_type res
            = m_sbuf->sputc(whitespace ? std::toupper(c) : c);
                
        whitespace = ctype.is(ctype.space | ctype.punct, c);
        return res;
    }
private:
    bool whitespace;
    const std::ctype<char>& ctype;
    std::streambuf* m_sbuf;
};

int main()
{
    stream_buffer sb(std::cout);
    std::ostream os(&sb);
    os << "hello my name is david.how are you";
}