[phobos] isStringLike

Walter Bright via phobos phobos at puremagic.com
Mon Oct 26 14:27:37 PDT 2015

On 10/26/2015 9:27 AM, Dmitry Olshansky via phobos wrote:
> Agreed. That is my opinion as well, however luck of any attention from you and 
> Walter led to the point where we
> need (a) and (b) to work right now and we hacked it (somewhat of speaking for 
> the community here, correct me if I'm wrong).

My recommendation was to remove the alias this in DirEntry that tried to turn it 
into a string. A DirEntry is not a wrapper for a string, in particular, it does 
not support range primitives, which is why the string functions failed when 
changed to have InputRange parameters. Adding range primitives to DirEntry would 
cause other weird problems, because DirEntry is fundamentally not a range (a 
range 'consumes' its data via popFront() which makes no sense for DirEntry).

Yes, that breaks:

     DirEntry direntry;

which must be rewritten as:

     DirEntry direntry;

and we're not supposed to break existing code. But the alternative, which is 
redoing every template that accepts an InputRange, seems an awfully heavy 
burden. Even if we do this change pervasively in Phobos, how does that help 
anyone else who uses InputRanges?

Tl,dr: the alias this in DirEntry is an abusive bad practice, and should never 
have happened.

More information about the phobos mailing list