I was trying to build the boost tools (v1.51.0) and ran into the error pasted below. Should this be concerning? - Jeff Performing configuration checks - has_icu builds : no ...patience... ...patience... ...found 2720 targets... ...updating 3 targets... compile-c-c++ ..\build\boost\regression\msvc-9.0\release\link-static\threading-multi\library_status.obj library_status.cpp regression\src\library_status.cpp(633) : error C2440: 'initializing' : cannot convert from 'const boost::filesystem::path::string_type' to 'std::basic_string<_Elem,_Traits,_Ax>' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] No constructor could take the source type, or constructor overload resolution was ambiguous regression\src\library_status.cpp(761) : error C2664: 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::append(const std::basic_string<_Elem,_Traits,_Ax> &)' : cannot convert parameter 1 from 'const boost::filesystem::path::string_type' to 'const std::basic_string<_Elem,_Traits,_Ax> &' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] Reason: cannot convert from 'const boost::filesystem::path::string_type' to 'const std::basic_string<_Elem,_Traits,_Ax>' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called ..\boost/test/impl/execution_monitor.ipp(948) : warning C4535: calling _set_se_translator() requires /EHa regression\src\library_status.cpp(899) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'const boost::filesystem::path::string_type' (or there is no acceptable conversion) c:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\INCLUDE\xstring(914): could be 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const std::basic_string<_Elem,_Traits,_Ax> &)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] c:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\INCLUDE\xstring(919): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const _Elem *)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] c:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\INCLUDE\xstring(924): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(_Elem)' with [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char> ] while trying to match the argument list '(std::string, const boost::filesystem::path::string_type)' call "C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"..\build\boost\regression\msvc-9.0\release\link-static\threading-multi\library_status.obj.rsp" ...failed compile-c-c++ ..\build\boost\regression\msvc-9.0\release\link-static\threading-multi\library_status.obj... ...skipped <p..\build\boost\regression\msvc-9.0\release\link-static\threading-multi>library_status.exe for lack of <p..\build\boost\regression\msvc-9.0\release\link-static\threading-multi>library_status.obj... ...skipped <p..\dist\bin>library_status.exe for lack of <p..\build\boost\regression\msvc-9.0\release\link-static\threading-multi>library_status.exe... ...failed updating 1 target... ...skipped 2 targets...