Re: array size known/not known in compile time

* James Kanze:


Money? What money? <g> Wish I had, but although committee work is not
economically possible for me[1] -- someone would have to "sponsor"
this in the committee -- I can contribute some time & effort.

When I fixed up the spec[2] code I presented earlier so that it passed
compilation[3], I found three things requiring compiler support:

  A Detecting the context the DSA (Dynamically Specified Array) is used
    in.

    E.g., for Visual C++ dynamic stack allocation is UB in a 'catch', so
    within a Visual C++ 'catch' it must be replaced with ordinary
    slow dynamic allocation (I bet many a programmer has fallen into the
    trap of using MS's charset conversion macros within 'catch'! --
    support for DSAs would help to remove that bug-attractor).

    Also, it would be catastrophic to use it at namespace scope.

  B Doing the stack allocation in the proper call context.

    For the code I had to define macros that allocate and pass a pointer
    to the allocated memory to the dynspec_array constructor.

    This problem could alternatively, possibly, be solved by allowing
    formal arguments to have defaults specified in terms of earlier
    arguments, but that would seemingly require a well-defined specified
    order of evaluation (which we all want, but, seemingly, for some
    reason nobody dares to put it to the committee).

 C Support initializer lists.

    Definining an AND macro for the comma is a kludge. Perhaps Andrei
    knows some super-duper solution, but I sure don't. Anyway, when it
    can't be done without using macro evilness, language support is
    indicated.

If not for this, and perhaps other things I haven't encountered or
thought of so far, a library solution could probably be a "good enough"
solution. So there is a strong connection to the thread on the D
language, what can reasonably be implemented as library solutions.
Perhaps more problems requiring language support will pop up when or if
I try to add multi-dimensional support; so far it's single-dimension.

Notes:
[1] I play the guitar because I could never afford a keyboard. In my
    teens I bicycled to secondary school, some 20 miles?, to use the
    electronic organ there. I also wanted to do electronics, but,
    unable to afford that hobby, except by experimenting with bits and
    pieces salvaged from old radios & donated to me by a radio
    amateur (a friend of my father), I ended up programming, which if
    need be can be done on paper -- and I did that.
[2] <url: http://preview.tinyurl.com/ycb9x7>
[3] <url: http://home.no.net/alfps/misc/dsa/v0_spec_test.cpp>

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