On Wed, 30 Mar 2005 15:16:07 -0500, Beman Dawes wrote
"Martin" <adrianm@touchdown.se> wrote in message
Couple thoughts below....
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.
If the is_* functions return false, rather than throwing, then testing for the negative of a is_* function becomes unreliable. Does !is_directory( "foo" ) mean that "foo" is a file, or is is just missing? The programmer would have to write exists("foo") && is_accessible("foo") && !is_directory("foo").
Why not: enum exists_check { CHECK, NO_CHECK }; bool is_directory( path p, exists_check = CHECK); Always returns false if directory doesn't exist...
That could be simplified by providing an is_file() function (as suggested by Jeff Garland recently), but then we have to define exactly what a file is. Is a socket a file? Is a device a file? Or what POSIX calls a "regular file"? How does that translate to Windows?
I think I already said this, but just to be sure:
Is a socket a file?
No
Is a device a file?
No
Or what POSIX calls a "regular file"?
Yes
How does that translate to Windows?
Since there are no simlinks is_file() == !is_directory().
- Why doesn't last_write_time return a boost::ptime
That was a concious decision to limit coupling. That is, to avoid Boost libraries which are not part of TR1. I'd like the Boost version to be identical to what gets proposed to the standards committee, and unless Boost Date-Time gets proposed and accepted, that means it can't be used.
This can be trivially implemented in convenience functions since date-time has added a from_time_t function for posix_time. Basically you just need a thin veneer over the current functions: #include "boost/date_time/posix_time/conversion.hpp" //sorry can't think of a good function name.... inline boost::posix_time::ptime last_write_time_as_ptime( const path & ph ) { using boost::posix_time; return from_time_t(last_write_time( const path & ph )); } I'm not suggesting Beman add this to filesystem core -- just pointing out that it can be done trivially with an add-on. Jeff