Re: [boost] [filesystem] Major changes before standardization

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-11-15 19:31:27

Beman Dawes wrote:
> That still leaves the question of single path vs separate path and
> wpath classes. A single path class looks very good in a lot of ways
> but we still have to decide how to deal with this case on a dual
> narrow/wide O/S:
>    path p( "foo" );
>    p /= L"bar";
>
> How about a rule that if any portion of a path is wide, the entire
> path gets converted to wide?

It's either that, or preserving the original width (thickness?). I'm not 
sure which is better, but see below.

> What about directory iteration? Is that wide or narrow? Don't
> directory_iterators have to come as two types, narrow and wide?

With a path+wpath design, it's the user's choice. Iterating over a path 
returns a narrow iterator, and iterating over a wpath returns a wide 
iterator.

With a single path, we have two options. Do as above, or choose a preferred 
character type whenever the library needs to return a path to the user (that 
may or may not vary depending on the filesystem the path points to.)

In the latter case, it makes sense to make operator/= preserve the width of 
the returned path; presumably the library had its reasons to choose one over 
the other.

See, I was right about the single path design creating more problems. ;-) 
path+wpath looks almost trivial in comparison.