The following code does not successfully compile: boost::ptr_map<int,int> testmap; testmap.erase(5); The compiler (MSVC 7.1) complains that the identifier "find" is unknown inside the erase function (see below). The class does have a find function as "testmap.find(5)" compiles as expected. I expect it's a mismatch with the embedded classes. Taken directly from associate_ptr_container.hpp: size_type erase( const key_type& x ) // nothrow { BOOST_ASSERT( !this->empty() ); iterator i = find( x ); // ERROR ON THIS LINE if( i == this->end() ) return 0; this->remove( i ); return this->c_private().erase( i.base() ); } The following workaround does work at least, but the above should also, shouldn't it? testmap.erase( testmap.find(5) ); -- Bill Buklis --