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digitalmars.D.bugs - [Issue 8686] New: Tuple cannot define with type that has only mutable opEquals

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=8686

           Summary: Tuple cannot define with type that has only mutable
                    opEquals
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: regression
          Priority: P2
         Component: Phobos
        AssignedTo: nobody puremagic.com
        ReportedBy: zan77137 nifty.com


--- Comment #0 from SHOO <zan77137 nifty.com> 2012-09-18 07:01:43 PDT ---
On git head, this code doesn't work:
-------------------------
import std.typecons;

struct S
{
    bool opEquals(T)(T a) { return false; }
}

void main(string[] args)
{
    auto t = tuple(S.init);
}

-------------------------
RESULT:
-------------------------
import\std\typecons.d(432): Error: template main.S.opEquals does not match any
function template declaration
main.d(5): Error: template main.S.opEquals cannot deduce template function from
argument types !()(const(S))

-------------------------

This problem is probably caused by this commit:
https://github.com/D-Programming-Language/phobos/commit/3c878f4b90670b46854fc66a09a8f68995fdb4ea

This implementation forces opEquals() const on the type that it controls.
Add a further condition that is to define the method if needed to constraint-if
to avoid it.

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Sep 18 2012
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=8686


Kenji Hara <k.hara.pg gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |pull, rejects-valid


--- Comment #1 from Kenji Hara <k.hara.pg gmail.com> 2012-09-18 08:45:51 PDT ---
https://github.com/D-Programming-Language/phobos/pull/803

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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--- Comment #2 from github-bugzilla puremagic.com 2012-09-18 09:44:26 PDT ---
Commits pushed to master at https://github.com/D-Programming-Language/phobos

https://github.com/D-Programming-Language/phobos/commit/414ca6ffd211940d55d598e8a751090fb362da4c
fix Issue 8686 - Tuple cannot define with type that has only mutable opEquals

We cannot show better error message for mismatching tuple lengths, because
compiler would *always* try to instantiate const opEquals.

I also added tests for exhaustive opEquals signatures - const or mutable, and
template or not

https://github.com/D-Programming-Language/phobos/commit/7f5d95adf106a2a3cc1a8439b20cdafa5a8688f3
Merge pull request #803 from 9rnsr/fix8686

Issue 8686 and others, Tuple.opEquals and opCmp does not work in some cases

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Sep 18 2012
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=8686


Kenji Hara <k.hara.pg gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


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Sep 22 2012