Boost C++ Libraries: Ticket #4399: Make the free function 'size' support the uBLAS traits system and better work with expression types

attachment set

Fri, 02 Jul 2010 22:12:41 GMT

attachment → size-allow_expr_and_break_back_comp.patch

Adds the use of uBLAS type traits, simplifies the interaction with expression types, replaces the 'size<tag>' function with the 'size_by_tag<tag>' function.

Fri, 02 Jul 2010 22:13:22 GMT

I've tried to change the 'size' operation without affecting its syntax but I've failed.

More specifically, the problem is given by one of the polymorphic version of size:

    template <typename TagT, typename ExprT>
    typename ExprT::size_type size(ExprT const& e);

which I've initially transformed into

    template <typename TagT, typename MatrixExprT>
    typename matrix_traits<MatrixExprT>::size_type size(matrix_expression<ExprT> const& me);

See the thread http://lists.boost.org/MailArchives/ublas/2010/06/4362.php for more details.

So, my solution is to break back compatibility by removing that version of size and introducing a new free function (e.g., size_by_tag) with the same semantic.

I attach a patch for the size operation and the related test suite.

attachment set

Mon, 20 Sep 2010 21:13:05 GMT

attachment → size-allow_expr.patch

Patch for size.hpp which is back compatible.

Mon, 20 Sep 2010 21:27:15 GMT

At the end I was able to create a patch for size.hpp which does not break back compatibility. So ignore the initially submitted patch (size-allow_expr_and_break_back_comp.patch).

I admit the real credits go to Daniel & Stefan, two guys that suggested to me the way to go. For more info see: http://groups.google.com/group/comp.lang.c++.moderated/browse_thread/thread/bd5080b28865f826

Summary of changes:

Use of ublas type-traits system (e.g. typename matrix_traits<M>::size_type).
Explicit use of matrix_/vector_expression in function arguments (e.g. size(matrix_expression<M> const& m).
Call to size<1>(v), with v a vector expression, is legal and returns the length of the vector-
Do you like it?

anonymous — Wed, 06 Oct 2010 13:28:41 GMT

patch applied and commited in trunk

owner, version, milestone changed

David Bellot — Sun, 10 Oct 2010 12:29:29 GMT

owner changed from Gunter to David Bellot
version Boost 1.44.0 → Boost Development Trunk
milestone Boost 1.44.0 → Boost-1.45.0

status changed; resolution set

David Bellot — Sun, 10 Oct 2010 12:29:51 GMT

status new → closed
resolution → fixed