Array slice initialization with implicitly castable type

[dlangBugzillaToGithub]

bearophile_hugs reported this on 2013-01-20T15:36:26Z

Transfered from https://issues.dlang.org/show_bug.cgi?id=9363

CC List

• andrej.mitrovich (@AndrejMitrovic)

Description

This code works:

import std.typecons: Typedef;
alias Typedef!(int[]) MyArray;
void main() {
    MyArray arr;
    arr.length = 10;
    arr[] = 0;
}


While this:


import std.typecons: Typedef;
alias Typedef!(ubyte[]) MyArray;
void main() {
    MyArray arr;
    arr.length = 10;
    arr[] = 0;
}



Gives (dmd 2.062alpha):

...\dmd2\src\phobos\std\typecons.d(2811): Error: cannot implicitly convert expression (v) of type int to ubyte[]
temp.d(6): Error: template instance std.typecons.Typedef!(ubyte[], null).Typedef.Proxy!(Typedef_payload).opSliceAssign!(Typedef!(ubyte[], null), int) error instantiating

[dlangBugzillaToGithub]

andrej.mitrovich (@AndrejMitrovic) commented on 2013-01-21T07:36:05Z

std.typecons.Proxy is really poorly designed. Essentially every possible operator is shoved in there without doing any sort of check on what is being wrapper (except for the one check for classes).

Btw please don't use the Platform field unless it's a platform-specific bug, thanks.

[dlangBugzillaToGithub]

andrej.mitrovich (@AndrejMitrovic) commented on 2013-01-21T07:36:32Z

(In reply to comment #1)
> wrapper

I mean wrapped.

[dlangBugzillaToGithub]

bearophile_hugs commented on 2013-01-21T09:15:34Z

(In reply to comment #1)

> Btw please don't use the Platform field unless it's a platform-specific bug,
> thanks.

The Platform tag was set to Windows because the error message that I have put here comes from Windows. It doesn't mean it's a Windows-only problem.