SMESH fails to build with GCC 12

[hobbes1069]

Fedora Rawhide has updated to gcc 12 and several packages are failing to build including SMESH which has the following error:

/builddir/build/BUILD/smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx: In member function 'void SMESH_MeshEditor::sweepElement(const SMDS_MeshElement*, const std::vector<std::_Rb_tree_iterator<std::pair<const SMDS_MeshNode* const, std::__cxx11::list<const SMDS_MeshNode*> > > >&, std::__cxx11::list<const SMDS_MeshElement*>&, size_t, SMESH_SequenceOfElemPtr&)':
/builddir/build/BUILD/smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx:4310:18: error: no matching function for call to 'swap(std::vector<bool>::reference, std::vector<bool>::reference)'
 4310 |         std::swap( isSingleNode[0], isSingleNode[1] );
      |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/12/bits/exception_ptr.h:43,
                 from /usr/include/c++/12/exception:168,
                 from /usr/include/boost/smart_ptr/bad_weak_ptr.hpp:21,
                 from /usr/include/boost/smart_ptr/detail/shared_count.hpp:25,
                 from /usr/include/boost/smart_ptr/shared_ptr.hpp:17,
                 from /usr/include/boost/shared_ptr.hpp:17,
                 from /builddir/build/BUILD/smesh-9.7.0.1/src/SMESH/src/SMESHDS/SMESH_Controls.hxx:32,
                 from /builddir/build/BUILD/smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.hxx:33,
                 from /builddir/build/BUILD/smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx:27:
/usr/include/c++/12/bits/move.h:196:5: note: candidate: 'std::_Require<std::__not_<std::__is_tuple_like<_Tp> >, std::is_move_constructible<_Tp>, std::is_move_assignable<_Tp> > std::swap(_Tp&, _Tp&) [with _Tp = _Bit_reference; _Require<__not_<__is_tuple_like<_Tp> >, is_move_constructible<_Tp>, is_move_assignable<_Tp> > = void]' (near match)
  196 |     swap(_Tp& __a, _Tp& __b)
      |     ^~~~
/usr/include/c++/12/bits/move.h:196:5: note:   conversion of argument 2 would be ill-formed:
/builddir/build/BUILD/smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx:4310:51: error: cannot bind non-const lvalue reference of type 'std::_Bit_reference&' to an rvalue of type 'std::vector<bool>::reference'
 4310 |         std::swap( isSingleNode[0], isSingleNode[1] );
      |                                     ~~~~~~~~~~~~~~^
/usr/include/c++/12/bits/move.h:220:5: note: candidate: 'template<class _Tp, long unsigned int _Nm> std::__enable_if_t<std::__is_swappable<_Tp>::value> std::swap(_Tp (&)[_Nm], _Tp (&)[_Nm])'
  220 |     swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
      |     ^~~~

[StefanBruens]

This should be reported to the upstream SALOME project. It may even be fixed already, upstream is at 9.8.0.

Two solutions:

• Use a recent GCC libstdc++, see gcc-mirror/gcc@5943493
• Use a more standards compliant solution, working an all compilers:
  std::vector<bool>::swap( isSingleNode[0], isSingleNode[1] );

[hobbes1069]

I added a using std::swap and changed it to just swap and that fixed it for now.

[trelau]

@hobbes1069 is this still relevant or can it be closed?

[hobbes1069]

9.8.0.2 still exhibits the same problem for me.

My workaround for now is:

Index: smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx
===================================================================
--- smesh-9.7.0.1.orig/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx
+++ smesh-9.7.0.1/src/SMESH/src/SMESH/SMESH_MeshEditor.cxx
@@ -4304,10 +4304,11 @@ void SMESH_MeshEditor::sweepElement(cons
       bool sameOrder = ( Abs( i2 - i1 ) == 1 ) ? ( i2 > i1 ) : ( i2 < i1 );
       if ( sameOrder )
       {
-        std::swap( itNN[0],    itNN[1] );
+		std::swap( itNN[0],    itNN[1] );
         std::swap( prevNod[0], prevNod[1] );
         std::swap( nextNod[0], nextNod[1] );
-        std::swap( isSingleNode[0], isSingleNode[1] );
+        using std::swap;
+        swap( isSingleNode[0], isSingleNode[1] );
         if ( nbSame > 0 )
           sames[0] = 1 - sames[0];
         iNotSameNode = 1 - iNotSameNode;

[hobbes1069]

While a local build succeeded the official build failed with a new error on Fedora Rawhide:

/builddir/build/BUILD/smesh-9.8.0.2/src/Netgen/libsrc/core/table.hpp: At global scope:
/builddir/build/BUILD/smesh-9.8.0.2/src/Netgen/libsrc/core/table.hpp:104:26: error: redefinition of 'size_t* ngcore::TablePrefixSum(FlatArray<unsigned int, unsigned int>)'
  104 |   NETGEN_INLINE size_t * TablePrefixSum (FlatArray<size_t> entrysize)
      |                          ^~~~~~~~~~~~~~