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digitalmars.D.bugs - [Issue 22979] New: "Pointers-to-member" with attributes


          Issue ID: 22979
           Summary: "Pointers-to-member" with attributes
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: josipp live.de

Hi all, I am aware of the nonsensical delegate -> function conversion
sequence for non-static member functions, as demonstrated by

class Class { int doubling(int x) { return x * 2; } }
void main()
    int function(int) fptr = &Class.doubling;  // typechecks!


However, there is some deeper unsound compiler reasoning going on.


//                                vvvvv notice the member fn attribute
class Class { int doubling(int x) inout { return x * 2; } }

void main()
    int function(int) fptr = &Class.doubling;


dmd fails with
 Error: cannot implicitly convert expression `& doubling`
of type `int function(int x) inout` to `int function(int)` Adjust the type of fptr it shall be then. Alas... no. ```d [...] void main() { int function(int) inout fptr = &Class.doubling; } ``` fails with
 Error: `const`/`immutable`/`shared`/`inout`/`return` attributes
are only valid for non-static member functions But when done with `auto`, it says ```d [...] void main() { auto fptr = &Class.doubling; pragma(msg, typeof(fptr)); // int function(int) inout } ``` What gives? --
Apr 03 2022