[boost] Re: path::leaf()

From: Rainer Deyke (rainerd_at_[hidden])
Date: 2003-08-21 19:51:01

David Abrahams wrote:
> "Rainer Deyke" <rainerd_at_[hidden]> writes:
>
>> David Abrahams wrote:
>>> A single component of a path is still a path, and it
>>> shouldn't devolve into a string.
>>
>> I disagree.  While a path with just one component can exist, a
>> single path component is no more a path than an element in an array
>> of integers is itself an array of integers.
>> A single component of a path is a name, and therefore naturally
>> represented by 'std::string'.
>
> Are you seriously saying that path("foo") is not a path?

No.  "foo" is a path element.  path("foo") is a path with one element.

>  If you want
> to make paths into containers of strings, give them iterators and
> operator[], and I'll accept the name back() as a way to get the leaf
> string.

Paths already have iterators to iterate over the path elements.  I agree
that 'back' would be a better name what is currently called 'leaf', since
this frees the 'leaf' name to return a path instead of a string.

>> If 'p' is a native path
>
> Is there such a thing as a "native path"?  I thought all path strings,
> even if they began as native, got converted immediately into some
> "portable generic" format internally.

It is my understanding that paths are implemented as
std::vector<std::string> or something similar, where the individual strings
can contain slashes if the underlying filesystem allows it.  It would be a
shame if filesystem::path was unable to represent legal native paths just
because they contain characters which have special meaning in the portal
path grammar.

>> then 'p.leaf()' may contain any character that is supported by the
>> native file system, which may include slashes.  When 'p.leaf()' is
>> then converted back into a 'filesystem::path', the resulting path
>> will have different sematics than intended.  This strikes me as very
>> dangerous.
>
> Oh, is that what happens now?  Yipes!

Yipes indeed.

-- 
Rainer Deyke - rainerd_at_[hidden] - http://eldwood.com