[Issue 1650] New: Incorrect overload selected with IFTI

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=1650

           Summary: Incorrect overload selected with IFTI
           Product: D
           Version: 1.023
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla at digitalmars.com
        ReportedBy: sean at f4.ca


Given the following code:

    void proc(T)( T val )
    {
        printf( "proc:T\n" );
    }

    void proc(T,U=void)( T[] val )
    {
        printf( "proc:T[]\n" );
    }

    void main()
    {
        proc( 0 );
        proc( "abc".dup );
    }

I would expect to see:

    proc:T
    proc:T[]

Because proc:T[] is more specialized and thus should be preferred for the
second call.  Instead, it prints:

    proc:T
    proc:T

Interestingly, moving the dummy parameter to the first function:

    void proc(T,U=void)( T val )
    {
        printf( "proc:T\n" );
    }

    void proc(T)( T[] val )
    {
        printf( "proc:T[]\n" );
    }

    void main()
    {
        proc( 0 );
        proc( "abc".dup );
    }

Results in the expected behavior:

    proc:T
    proc:T[]

I can only assume this means that the dummy parameters required to support
overloading are considered for determining how specialized a particular
function is, even though they are not used in the function parameter list.


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