https://svn.boost.org/trac10/ticket/9 <pre class="wiki"> I am doing internal testing on a pre-release version of the Borland C++ compiler. config/test/config_info.cpp generates an ambiguity with Borland C++ 5.5.1 when using the STLPort library in place of the currently shipping RogueWave. I see that other highly-conformant compilers are also failing this test. I have confirmed that with g++ 2.95 the error given is the same as the error I see with Borland's compiler (w/STLPort). Here is a code sample that I narrowed from config_info.cpp: #include&lt;wchar.h&gt; #include&lt;functional&gt; template&lt;class S,class&gt;class AA: unary_function &lt;int, S&gt;{}; template&lt;class S,class T&gt;AA&lt;S,T&gt;mem_fun(S(T::*)()const) {} class BB{public:void ff()const{}}; void test(){mem_fun(BB::ff);} /* Error E2015 config_test.cpp 6: Ambiguity between '_STL::_STL::const_mem_fun_t&lt;BB&gt; mem_fun&lt;void,BB&gt;(void (BB::*)() const)' and 'AA&lt;void,BB&gt; mem_fun&lt;void,BB&gt;(void (BB::*)() const)' in function test() */ </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/9 Trac 1.4.3 beman_dawes Mon, 05 Nov 2001 19:23:01 GMT https://svn.boost.org/trac10/ticket/9#comment:2 https://svn.boost.org/trac10/ticket/9#comment:2 <ul> <li><strong>status</strong> <span class="trac-field-old">assigned</span> → <span class="trac-field-new">closed</span> </li> </ul> <pre class="wiki">Logged In: YES user_id=53943 The test case you gave above is invalid in at least two respects: 1. unary_function is used without std:: qualification. 2. You're trying to get the address of a non-static member function without using the address-of operator. Also, I doubt you're having a problem with config_info.cpp. It's more likely config_test.cpp. Please post a new bug report showing the compiler command line you're using with the unmodified boost code (what version?), and the error message you get with gcc. What OS do you use? </pre> Ticket