Fix compile with clang-3.5

[springmeyer]

Addresses #2459

[freenerd]

why is this better than the for (auto &each : loop before?

[daniel-j-h]

clang35's stdlib does not support the vector constructor that takes a size when the template argument is a moveable only type. This is a bug in its stdlib. To work around this we default construct the vector, then loop n times adding a new counter and initializing it explicitly.

[springmeyer]

@daniel-j-h is it really a bug in the standard library or clang-3.5 itself? I'm asking because the standard library was the same on the system this replicates on and g++ was not impacted, only clang.

[daniel-j-h]

I don't have the error here, but I thought the constructor was calling the atomic' deleted copy assignment operator. The stdlib implementation of the vector does this. Could also be that clang35 just picks a wrong assignment operator?

[freenerd]

did you run clang-format over this?

[springmeyer]

@freenerd - no, will run clang-format next. But first it looks like this is not compiling on compilers that are not clang-3.5:

In file included from /usr/include/c++/4.8/vector:62:0,
                 from /usr/include/boost/filesystem/path_traits.hpp:26,
                 from /usr/include/boost/filesystem/path.hpp:25,
                 from /home/travis/build/Project-OSRM/osrm-backend/include/contractor/contractor_config.hpp:31,
                 from /home/travis/build/Project-OSRM/osrm-backend/include/contractor/contractor.hpp:31,
                 from /home/travis/build/Project-OSRM/osrm-backend/src/contractor/contractor.cpp:1:
/usr/include/c++/4.8/bits/stl_construct.h: In instantiation of ‘void std::_Construct(_T1*, _Args&& ...) [with _T1 = std::atomic<long unsigned int>; _Args = {std::atomic<long unsigned int>}]’:
/usr/include/c++/4.8/bits/stl_uninitialized.h:75:53:   required from ‘static _ForwardIterator std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = std::move_iterator<std::atomic<long unsigned int>*>; _ForwardIterator = std::atomic<long unsigned int>*; bool _TrivialValueTypes = false]’
/usr/include/c++/4.8/bits/stl_uninitialized.h:117:41:   required from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = std::move_iterator<std::atomic<long unsigned int>*>; _ForwardIterator = std::atomic<long unsigned int>*]’
/usr/include/c++/4.8/bits/stl_uninitialized.h:258:63:   required from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, std::allocator<_Tp>&) [with _InputIterator = std::move_iterator<std::atomic<long unsigned int>*>; _ForwardIterator = std::atomic<long unsigned int>*; _Tp = std::atomic<long unsigned int>]’
/usr/include/c++/4.8/bits/stl_uninitialized.h:281:67:   required from ‘_ForwardIterator std::__uninitialized_move_if_noexcept_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&) [with _InputIterator = std::atomic<long unsigned int>*; _ForwardIterator = std::atomic<long unsigned int>*; _Allocator = std::allocator<std::atomic<long unsigned int> >]’
/usr/include/c++/4.8/bits/vector.tcc:415:43:   required from ‘void std::vector<_Tp, _Alloc>::_M_emplace_back_aux(_Args&& ...) [with _Args = {}; _Tp = std::atomic<long unsigned int>; _Alloc = std::allocator<std::atomic<long unsigned int> >]’
/usr/include/c++/4.8/bits/vector.tcc:101:54:   required from ‘void std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {}; _Tp = std::atomic<long unsigned int>; _Alloc = std::allocator<std::atomic<long unsigned int> >]’
/home/travis/build/Project-OSRM/osrm-backend/src/contractor/contractor.cpp:501:50:   required from here
/usr/include/c++/4.8/bits/stl_construct.h:75:7: error: use of deleted function ‘std::atomic<long unsigned int>::atomic(const std::atomic<long unsigned int>&)’
     { ::new(static_cast<void*>(__p)) _T1(std::forward<_Args>(__args)...); }
       ^
In file included from /home/travis/build/Project-OSRM/osrm-backend/include/util/dynamic_graph.hpp:13:0,
                 from /home/travis/build/Project-OSRM/osrm-backend/include/contractor/graph_contractor.hpp:6,
                 from /home/travis/build/Project-OSRM/osrm-backend/src/contractor/contractor.cpp:3:
/usr/include/c++/4.8/atomic:658:7: error: declared here
       atomic(const atomic&) = delete;
       ^

[springmeyer]

@TheMarex sorry, this was not passing yet. Per #2459 (comment) I wonder if this code can be re-written to avoid this brittle use of atomics.