Johnathan,
What are you trying to do? <
I believe that we have already discussed this. But since you ask: template<typename T, typename Tr, typename Alloc, typename Mode> class normalized_indirect_streambuf : public boost::iostreams::detail:: indirect_streambuf<T, Tr, Alloc, Mode> { public: typedef boost::iostreams::detail:: indirect_streambuf<T, Tr, Alloc, Mode> base_type; normalized_indirect_streambuf(void) : base_type() { } protected: std::streamsize _Xsgetn_s(char_type* _Ptr, size_t _Ptr_size, std::streamsize _Count); int_type underflow() { buffer_type& buf = in(); if((buf.size() - pback_size_) == 0) return traits_type::eof(); return base_type::underflow(); } }; template<typename T, typename Tr, typename Alloc, typename Mode> std::streamsize normalized_indirect_streambuf<T, Tr, Alloc, Mode>:: _Xsgetn_s(char_type* s, size_t _Ptr_size, std::streamsize n) { using namespace std; buffer_type& buf = in(); if (!gptr() && buf.size() > 0) init_get_area(); streamsize total = 0; do { // Fill request from buffer. if (streamsize avail = std::min(n, static_cast<streamsize>(egptr() - gptr()))) { traits_type::copy(s, gptr(), avail); gbump((int) avail); total += avail; s += avail; n -= avail; } else { // Read from source. streamsize to_read = buf.size() - pback_size_; if(to_read <= n) { //if(to_read == 0) to_read = n; if(streamsize amt = obj().read(s, to_read, next_)) { s += amt; n -= amt; total += amt; if(amt < to_read) break; // probably EOF } else { // Something is screwed. Get out of dodge. break; } } else { if(traits_type::eq_int_type(traits_type::eof(), underflow())) break; } } } while(n > 0); return total; } The implementation avoids excessive copying by bypassing, under carefully defined circumstances, internal buffering and performing the read operation in-place.
Also, component_impl() is virtual, so you should be able to override it even though its private. <
I'm not sure how this helps; component_impl() returns a void*. What am I supposed to do, cast it? :-( Regards, George.