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digitalmars.D.bugs - [Issue 6551] New: [CTFE] struct constructor not recognized under weird conditions

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6551

           Summary: [CTFE] struct constructor not recognized under weird
                    conditions
           Product: D
           Version: unspecified
          Platform: All
        OS/Version: All
            Status: NEW
          Keywords: rejects-valid
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: mrmocool gmx.de


--- Comment #0 from Trass3r <mrmocool gmx.de> 2011-08-24 16:51:05 PDT ---
So there's a struct with a ubyte. To shut up dmd about implicit conversions I
added a constructor but it isn't recognized.

// this failes
immutable int dummy = init();
int init()
{
    uint x;
6:    auto p = F(x);
    return 0;
}

struct F
{
    ubyte th;
    this(uint x)
    { th = cast(ubyte) x; }
}

// while it works in this case
void main()
{
    uint x;
    auto p = F(x);
}

$ dmd -c posecells.d 
DMD v2.055 DEBUG
posecells.d(6): Error: cannot implicitly convert expression (x) of type uint to
ubyte
posecells.d(2): Error: cannot evaluate init() at compile time

Weird thing is, if you remove 'int' in front of 'dummy' it magically works.

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parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6551


Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |clugdbug yahoo.com.au
            Version|unspecified                 |D2
            Summary|[CTFE] struct constructor   |struct constructor not
                   |not recognized under weird  |recognized when forward
                   |conditions                  |referenced


--- Comment #1 from Don <clugdbug yahoo.com.au> 2011-09-01 04:30:48 PDT ---
This isn't a CTFE bug. Reduced test case:

uint NINE = 9;
typeof(F(NINE)) fails;

struct F
{
    ubyte th;
    this(uint x)
    { th = cast(ubyte) x; }
}

This is a forward reference issue. It compiles if you move the declaration of
'fails' past the declaration of F.

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