Tools to generate higher-quality error messages for template-based code?

Question

Concepts, that would render these tools unnecessary, are not part of C++11.

• STLFilt would have been one option but it is no longer maintained.

Answer 1

I have found Clang to generate the best error messages for heavily templated code. Of course verbosity is unavoidable in most cases, but it's still better than GCC or MSVC most of the time. Here's the Clang error message for the example code posted by AshleysBrain:

$ clang++ -std=c++11 -stdlib=libc++ -o dummy dummy.cpp 
In file included from dummy.cpp:1:
In file included from /usr/include/c++/v1/vector:243:
In file included from /usr/include/c++/v1/__bit_reference:15:
In file included from /usr/include/c++/v1/algorithm:594:
/usr/include/c++/v1/memory:1425:36: error: calling a private constructor of class 'std::__1::unique_ptr >'
                ::new ((void*)__p) _Tp(_STD::forward<_Args>(__args)...);
                                   ^
/usr/include/c++/v1/memory:1358:14: note: in instantiation of function template specialization
      'std::__1::allocator_traits > >
      >::__construct >, std::__1::unique_ptr > &>' requested here
            {__construct(__has_construct(),
             ^
/usr/include/c++/v1/vector:781:25: note: in instantiation of function template specialization
      'std::__1::allocator_traits > >
      >::construct >, std::__1::unique_ptr > &>' requested here
        __alloc_traits::construct(__a, _STD::__to_raw_pointer(this->__end_), *__first);
                        ^
/usr/include/c++/v1/vector:924:9: note: in instantiation of function template specialization
      'std::__1::vector >,
      std::__1::allocator > >
      >::__construct_at_end > *>' requested here
        __construct_at_end(__x.__begin_, __x.__end_);
        ^
dummy.cpp:7:37: note: in instantiation of member function 'std::__1::vector >, std::__1::allocator > >
      >::vector' requested here
        std::vector> bar = foo;
                                           ^
/usr/include/c++/v1/memory:1997:5: note: declared private here
    unique_ptr(const unique_ptr&);
    ^
1 error generated.

It's still long and ugly, but in my opinion much clearer regarding what/where the problem is.