Compile failure in C++11 mode with g++-4.6

[c42f]

Hi guys,

Thanks for the great library. I've just started playing with it for point cloud matching of airborne lidar scans, and so far it's looking much more robust than I could reasonably have expected :-)

I've come across one small issue with the compile - we build all our stuff in C++11 mode using g++-4.6 or later, and I'm getting a compile error, which appears to relate to the boost initialization stuff. (The build works fine if I compile in C++98 mode.)

The error is a horrible mess of template badness which I'll paste in below. I'm not sure whether it's possible to fix directly, but I'd be happy to make a patch which changes all this to use C array initialization and a small amount of parsing code to create the bibliography.

Here's the error I get with g++ (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3

In file included from /usr/include/c++/4.6/bits/stl_algobase.h:65:0,
                from /usr/include/c++/4.6/bits/stl_tree.h:63,
                from /usr/include/c++/4.6/map:60,
                from /home/cfoster/src/libpointmatcher-dev/pointmatcher/Bibliography.h:39,
                from /home/cfoster/src/libpointmatcher-dev/pointmatcher/Bibliography.cpp:36:
/usr/include/c++/4.6/bits/stl_pair.h: In constructor ‘std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = const char (&)[23], _U2 = const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&, <template-parameter-2-3> = void, _T1 = std::basic_string<char>, _T2 = std::map<std::basic_string<char>, std::basic_string<char> >]’:
/home/cfoster/ROAMES_git/Components/ThirdParty/cmake/build/dist/boost-1.54.0/include/boost/preprocessor/iteration/detail/local.hpp:37:1:   instantiated from ‘boost::assign_detail::generic_list<T>& boost::assign_detail::generic_list<T>::operator()(const U&, const U0&) [with U = char [23], U0 = boost::assign_detail::generic_list<std::pair<const char*, const char*> >, T = std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > >, boost::assign_detail::generic_list<T> = boost::assign_detail::generic_list<std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > > >]’
/home/cfoster/src/libpointmatcher-dev/pointmatcher/Bibliography.cpp:92:4:   instantiated from here
/usr/include/c++/4.6/bits/stl_pair.h:132:64: error: call of overloaded ‘map(const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&)’ is ambiguous
/usr/include/c++/4.6/bits/stl_pair.h:132:64: note: candidates are:
/usr/include/c++/4.6/bits/stl_map.h:197:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::initializer_list<std::pair<const _Key, _Tp> >, const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_map.h:183:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::map<_Key, _Tp, _Compare, _Alloc>&&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:172:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const std::map<_Key, _Tp, _Compare, _Alloc>&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:161:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_pair.h: In constructor ‘std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = const char (&)[20], _U2 = const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&, <template-parameter-2-3> = void, _T1 = std::basic_string<char>, _T2 = std::map<std::basic_string<char>, std::basic_string<char> >]’:
/home/cfoster/ROAMES_git/Components/ThirdParty/cmake/build/dist/boost-1.54.0/include/boost/preprocessor/iteration/detail/local.hpp:37:1:   instantiated from ‘boost::assign_detail::generic_list<T>& boost::assign_detail::generic_list<T>::operator()(const U&, const U0&) [with U = char [20], U0 = boost::assign_detail::generic_list<std::pair<const char*, const char*> >, T = std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > >, boost::assign_detail::generic_list<T> = boost::assign_detail::generic_list<std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > > >]’
/home/cfoster/src/libpointmatcher-dev/pointmatcher/Bibliography.cpp:103:4:   instantiated from here
/usr/include/c++/4.6/bits/stl_pair.h:132:64: error: call of overloaded ‘map(const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&)’ is ambiguous
/usr/include/c++/4.6/bits/stl_pair.h:132:64: note: candidates are:
/usr/include/c++/4.6/bits/stl_map.h:197:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::initializer_list<std::pair<const _Key, _Tp> >, const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_map.h:183:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::map<_Key, _Tp, _Compare, _Alloc>&&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:172:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const std::map<_Key, _Tp, _Compare, _Alloc>&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:161:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_pair.h: In constructor ‘std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = const char (&)[17], _U2 = const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&, <template-parameter-2-3> = void, _T1 = std::basic_string<char>, _T2 = std::map<std::basic_string<char>, std::basic_string<char> >]’:
/home/cfoster/ROAMES_git/Components/ThirdParty/cmake/build/dist/boost-1.54.0/include/boost/preprocessor/iteration/detail/local.hpp:37:1:   instantiated from ‘boost::assign_detail::generic_list<T>& boost::assign_detail::generic_list<T>::operator()(const U&, const U0&) [with U = char [17], U0 = boost::assign_detail::generic_list<std::pair<const char*, const char*> >, T = std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > >, boost::assign_detail::generic_list<T> = boost::assign_detail::generic_list<std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > > >]’
/home/cfoster/src/libpointmatcher-dev/pointmatcher/Bibliography.cpp:125:4:   instantiated from here
/usr/include/c++/4.6/bits/stl_pair.h:132:64: error: call of overloaded ‘map(const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&)’ is ambiguous
/usr/include/c++/4.6/bits/stl_pair.h:132:64: note: candidates are:
/usr/include/c++/4.6/bits/stl_map.h:197:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::initializer_list<std::pair<const _Key, _Tp> >, const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_map.h:183:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::map<_Key, _Tp, _Compare, _Alloc>&&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:172:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const std::map<_Key, _Tp, _Compare, _Alloc>&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:161:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_pair.h: In constructor ‘std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = const char (&)[19], _U2 = const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&, <template-parameter-2-3> = void, _T1 = std::basic_string<char>, _T2 = std::map<std::basic_string<char>, std::basic_string<char> >]’:
/home/cfoster/ROAMES_git/Components/ThirdParty/cmake/build/dist/boost-1.54.0/include/boost/preprocessor/iteration/detail/local.hpp:37:1:   instantiated from ‘boost::assign_detail::generic_list<T>& boost::assign_detail::generic_list<T>::operator()(const U&, const U0&) [with U = char [19], U0 = boost::assign_detail::generic_list<std::pair<const char*, const char*> >, T = std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > >, boost::assign_detail::generic_list<T> = boost::assign_detail::generic_list<std::pair<std::basic_string<char>, std::map<std::basic_string<char>, std::basic_string<char> > > >]’
/home/cfoster/src/libpointmatcher-dev/pointmatcher/Bibliography.cpp:147:4:   instantiated from here
/usr/include/c++/4.6/bits/stl_pair.h:132:64: error: call of overloaded ‘map(const boost::assign_detail::generic_list<std::pair<const char*, const char*> >&)’ is ambiguous
/usr/include/c++/4.6/bits/stl_pair.h:132:64: note: candidates are:
/usr/include/c++/4.6/bits/stl_map.h:197:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::initializer_list<std::pair<const _Key, _Tp> >, const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
/usr/include/c++/4.6/bits/stl_map.h:183:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(std::map<_Key, _Tp, _Compare, _Alloc>&&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:172:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const std::map<_Key, _Tp, _Compare, _Alloc>&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc> = std::map<std::basic_string<char>, std::basic_string<char> >]
/usr/include/c++/4.6/bits/stl_map.h:161:7: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const _Compare&, const allocator_type&) [with _Key = std::basic_string<char>, _Tp = std::basic_string<char>, _Compare = std::less<std::basic_string<char> >, _Alloc = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >, std::map<_Key, _Tp, _Compare, _Alloc>::allocator_type = std::allocator<std::pair<const std::basic_string<char>, std::basic_string<char> > >]
make[2]: *** [CMakeFiles/pointmatcher.dir/pointmatcher/Bibliography.cpp.o] Error 1
make[1]: *** [CMakeFiles/pointmatcher.dir/all] Error 2
make: *** [all] Error 2

[stephanemagnenat]

As I understand these errors, some template-based deduction becomes ambiguous with C++11 because of the extended expressivity of the language. I see two solutions:

1. make it work by adding the necessary explicit cast/template parameters/initializers/...
2. have an ifdef and use std::initializer_lists while using C++11

The solution 1. is the cleanest in my opinion.

[c42f]

Agreed that solution 1. is much better than 2.

After some investigation, I think the issue here may be that std::map now has additional constructors, and some of the conflict with the assign_detail::generic_list implicit conversion operator to std::map. Surprisingly, most of the expected hacks to work around this problem don't actually work (eg, explicitly calling the StringMap constructor, calling map_list_of with explicit types).

Introducing a layer of indirection does work however, I will submit a pull request.

[stephanemagnenat]

Thank you!

[stephanemagnenat]

Fixed by pull request #14.