• d-bugmail puremagic.com Apr 08 2007

http://d.puremagic.com/issues/show_bug.cgi?id=1111

           Summary: enum value referred to by another value of same enum is
                    considered as enum's base type, not enum type
           Product: D
           Version: 1.010
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: rejects-valid
          Severity: minor
          Priority: P3
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: deewiant gmail.com


A strange beetle, this, and difficult to summarize. Example code:

enum Enum : byte {
        NORMAL_VALUE = 0,
        REFERRING_VALUE = NORMAL_VALUE + 1,
        OTHER_NORMAL_VALUE = 2
}

void test(Enum e) {
}

void main() {
     test(Enum.NORMAL_VALUE);
     test(Enum.REFERRING_VALUE);
     test(Enum.OTHER_NORMAL_VALUE);
} 

The call on line 11, passing Enum.NORMAL_VALUE, fails unless the definition of
REFERRING_VALUE is changed to not refer to NORMAL_VALUE. Alternatively, set
REFERRING_VALUE just equal to NORMAL_VALUE (remove the "+ 1"). The error:

asdf.d(11): function asdf.test (Enum) does not match parameter types (byte)
asdf.d(11): Error: cannot implicitly convert expression (0) of type byte to
Enum

Fortunately, this can be worked around by referring to Enum.NORMAL_VALUE, as
opposed to just NORMAL_VALUE, in the definition of REFERRING_VALUE.

This might have something to do with Issue 633: when NORMAL_VALUE is used in an
expression, it is cast to Enum's base type, and left that way? This doesn't
explain why using the fully qualified name of NORMAL_VALUE works, though.


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