Boost C++ Libraries: Ticket #2294: Please improve test annotation

Dave Abrahams — Sat, 06 Sep 2008 03:06:36 GMT

I think I understand the bug now (though the text should still be improved) and I have a suggestion to make: on those compilers where the bug exists, make the constructor in question explicit so that you can't mistakenly end up with a dangling reference. I did that by brute force in my local copy by specializing optional<V const&> and adding "explicit" to the ctor.

Dave Abrahams — Mon, 08 Sep 2008 14:43:33 GMT

Suggested new text:

This failure is caused by a compiler bug, and as far as we can tell, can't be worked around in the library, although we think the library might be made safer with respect to this bug.

Specifics: the following simple test fails when it should succeed.

 #include <cassert>
int const x = 0;
struct A
{
   A(int const& y)
   {
       assert(&x == &y);
   }
};
int main()
{
   A a(x);  // direct initialization works fine
   A b = x; // copy initialization causes x to be copied before it is bound
}

The possible safety enhancement would be to cause the constructor in question to be explicit for optional<T const&>; that would prevent copy initialization.

Dean Michael Berris — Sun, 28 Nov 2010 23:26:25 GMT

Dave, can you be a little more explicit as to which file this text should go in? I'm prepared to make a patch but I can't see where the expected failure annotation should be changed.

anonymous — Mon, 29 Nov 2010 01:43:53 GMT

It's at status/explicit-failures-markup.xml.

Dean Michael Berris — Mon, 29 Nov 2010 02:05:32 GMT

Replying to anonymous:

It's at status/explicit-failures-markup.xml.

Thanks for the pointer. I see two expected failure markups for optional_test_ref, one entry for msvc-6.5 and msvc-7.1 and another for the GCC family of compilers.

I'll add the above text in both entries and whoever will apply should do the right thing.

attachment set

Dean Michael Berris — Mon, 29 Nov 2010 02:28:49 GMT

attachment → boost-optional-explicit-failures-markup-issue2294.diff

Proposed patch including the proposed text in the issue.

Marshall Clow — Fri, 07 Jan 2011 00:45:28 GMT

(In [67743]) Applied patch; refs #2294

owner changed

Marshall Clow — Fri, 07 Jan 2011 01:02:54 GMT

owner changed from Fernando Cacciola to Marshall Clow

status changed; resolution set

Marshall Clow — Sat, 08 Jan 2011 18:45:50 GMT

status new → closed
resolution → fixed

Fix merged to release branch in [67792]