[boost] [Filesystem] i18n

From: Martin (adrianm_at_[hidden])
Date: 2005-03-30 13:18:34

Didn't find any comments on the new filesystem implementation so here are mine 

- Would it be possible to store the new files in the vault? I find it 
inconvenient to check out a special branch just to read the documentation.

- I haven't compiled the new files but I have had a good look at the 
documentation and the source. My impression is that it is a very nice 
implementation. (All the #ifdefs make the source hard to follow but I'm not 
the maintainer)

- Specially I like the switch from default portable syntax to default native 
syntax. It means that I no longer need to change the default name checker in 
each application and that the "native_" prefix from the access functions are 
gone.
(Maybe the name checker could be a template parameter (with default "none") 
for those who still want to use it. Would complicate implementation of 
operations.)

The comments I have on the new implementation is:
- Operations are limited to std::string (and std::wstring on win32) as 
external type. Why not allow any range of characters? Current implementation 
will not work with const_string, flex_string and a basic_string with a custom 
allocator.

- Why not have a static locale member in the class instead of using the utf-8 
facet. The locale could then be used both for internal/external conversion via 
the codecvt facet and get operator< to work with a custom locale.
(for posix the locale would default to locale::global() with the utf-8 facet 
added)

I also had hopes for some new things that didn't appear in the new 
implementation.
- non-throwing is_* functions. I find it very inconvenient and error prune to 
put try/catch around each is_directory call. Calling is_accessible before 
every other is_* function is an option but not much easier and still leaves a 
risk for an exception if another process is accessing the file.
The throwing is_* functions also makes it impossible(?) to use the directory 
iterator with algorithms like remove_copy_if(directory_iterator(path), 
directory_iterator(), back_inserter(filelist), is_directory)
My suggestion is to add non-throwing overloads where a second parameter tells 
what the function should return in case of error. e.g. is_directory(path, 
true).

- The directory iterator is still very limited since you can't specify a 
filter (e.g. "*.txt"). If used on a win32 system with a mounted posix disk or 
a posix system with a CD problems might arise. (There is no portable way to 
tell if "FILE.TXT" matches "*.txt").

- Why doesn't last_write_time return a boost::ptime