On 03/01/08 09:40, Roland Schwarz wrote:
Larry Evans wrote:
I couldn't resist trying it now; ;-)
however, I'm getting wrong output :(
Hmm, I did not test it, but from looking at your source:
marg_ostream& mout(void) { return std::cout; }
gives you back std::cout, while it should hand back ; boost::iostreams::filtering_ostream out
The state is stored in out instance of course, not cout.
Right. So, should: <-- cut here -- #include "indent.hpp" typedef boost::iostreams::filtering_ostream marg_ostream; marg_ostream out; #include <iostream> marg_ostream& mout(void) { return out; } //#define DEBUG_PRINT void operator++(marg_ostream& sout) { #ifdef DEBUG_PRINT sout<<"operator++(marg_ostream&)\n"; #endif sout<<indent_in; } void operator--(marg_ostream& sout) { sout<<indent_out; #ifdef DEBUG_PRINT sout<<"operator--(marg_ostream&)\n"; #endif } ... int main(void) { ; indent_filter::push(out,2) ; out.push(std::cout) ; mout()<<"line1\n" ...
-- cut here -- work? With this change, I get compile errors like:
indent_test.cpp: In function 'marg_ostream& operator<<(marg_ostream&, const test*)': indent_test.cpp:60: error: no match for 'operator<<' in 'std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char>
&)(&((marg_ostream*)sout)->boost::iostreams::filtering_stream<boost::iostreams::output, char, std::char_traits<char>, std::allocator<char>, boost::iostreams::public_>::<anonymous>.boost::iostreams::detail::filtering_stream_base<boost::iostreams::chain<boost::iostreams::output, char, std::char_traits<char>, std::allocator<char> >, boost::iostreams::public_>::<anonymous>)), ((const char*)"*(test*)=")) << * a_test' /usr/include/c++/4.1.3/bits/ostream.tcc:67: note: candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>& (*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>]