Changed operator()(int, int...) && for array, and views.
- For const_view and regular type, returns value_type (i.e. a copy).
NB : does make a copy, not a move. Ok for scalar type. TODO: think for complicated types.
This allows codes like :
f(x)(0,0) where f : x-> matrix or const_view
to be correct in clef expression evaluation.
- For _view : return a value_type &, as before to allow :
A(....)(0,0) = rhs;
It is not possible to detect dangling refs in that case at compile time.
Added a security in TRIQS_ARRAYS_DEBUG mode to detect a dangling ref at run time,
i.e. the case where the view is "unique" (ref count ==1).
This would be a quite bad design anyway ...
- also :
- clean operator[] for vector (old workaround for old gcc...)
- add IsView flag in ISP impl class, for the impl. of operator() &&
- improve the mem_block and shared_block.
- the reference counting is now done in the mem_block and shared_block, removing the need of shared_ptr.
- speed tests shows that shared_ptr is very slow (due to thread safety?)
the new version is much better, though not perfect.
- Hence introducing weak views.
- also :
-- clean the guard mechanism for python (to allow returning from python without any python ref left).
-- clean code, add documentation for mem_block
-- remove nan init, which was not working, and corresponding test
-- serialisation of view still unchanged (need to forbid serialization of view ??).
- tests ok, incl. valgrind tests.
