[Bug 31] Keyword 'function' and pointer test broken for IsExpression

d-bugmail at puremagic.com d-bugmail at puremagic.com
Wed Apr 26 11:43:19 PDT 2006


bugzilla at digitalmars.com changed:

           What    |Removed                     |Added
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID

------- Comment #4 from bugzilla at digitalmars.com  2006-04-26 13:43 -------
>alias void function() fp;
>static if( is( fp == function ) ) printf( "6. function passes\n" );

fp is not declared as a function, it is declared as a pointer to a function. If
fp is declared as:
    alias void fp();
it will 'pass'.

>template isPointer( T )
>    const bool isPointer = is( T : T* );
>static if( isPointer!(int*) ) printf( "8. pointer passes\n" );

Here, int* is passed as T to isPointer. The is(T:T*) is evaluated as
is(int*:int**), and so it fails. To detect a pointer, use is(T:void*).

>class C { void fn() {} }
>     static if( is( typeof(C.fn) == function ) )
>         pragma( msg, "is function\n" );
>     static if( is( typeof(C.fn) == delegate ) )
>         pragma( msg, "is delegate\n" );
>prints "is function" if compiled.  Aren't non-static class functions 
>actually delegates?

No. Class functions are functions. A delegate is a pointer to a class function.


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