I am attempting to compare two std::map<string,string> objects in Boost.Test but am finding that it is trying to stream the std::pair< const string, string > that results from dereferencing the iterator. /* Simplified Example */ AUTO_TEST_CASE( Map_Same ) { std::map< std::string, std::string > x; std::map< std::string, std::string > y; BOOST_CHECK_EQUAL_COLLECTIONS( x.begin(), x.end(), y.begin(), y.end() ); } Results in: /usr/include/boost/test/utils/wrap_stringstream.hpp: In function 'boost::basic_wrap_stringstream<CharT>& boost::operator<<(boost::basic_wrap_stringstream<CharT>&, const T&) [with CharT = char, T = std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >]': /usr/include/boost/test/test_tools.hpp:641: instantiated from 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_coll_impl(Left, Left, Right, Right) [with Left = std::_Rb_tree_iterator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >

, Right = std::_Rb_tree_iterator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >]'

In my application the values a particular entry in the map will not reveal the problem, so I chose to suppress printing of the pair: typedef std::pair< const std::basic_string<char>,std::basic_string<char>

pair_type; BOOST_TEST_DONT_PRINT_LOG_VALUE( pair_type );

But alas, this did absolutely nothing. Confused, I tried: BOOST_CHECK_EQUAL( *x.begin(), *y.begin() ); And it compiled. Remove the suppression and the error returns. So the suppression works, just not in conjunction with BOOST_*_EQUAL_COLLECTIONS. Searching the mailing list revealed a post from 2005. http://article.gmane.org/gmane.comp.lib.boost.user/13146 He mentions as I also found that equal_coll_impl uses the stream operator directly on the dereferenced iterators. This *appears* to be bypassing the code that allows suppression. Though I may be wrong (I can rarely tell with boost). Can someone check on this and see if I am crazy? In the mean time I guess I just have to overload the stream operator. Regards, Thomas Suckow