[boost] [filesystem] Change "remove" function's return to void?

From: Beman Dawes (bdawes_at_[hidden])
Date: 2008-07-01 09:54:42

The remove(p) function is currently specified to return a bool with a 
value of exist(p) before the post-condition is established. The 
post-condition is !exists(p).

The original thought in providing this was that the return value might 
be useful and would cost nothing.

It turns out that providing this return value does have several costs:

* A call to exists() could be omitted if the actual system removal call 
succeeds. exists() is surprisingly expensive on some operating systems.

* It makes the remove() function less reliable in that it introduces a 
potential race condition.

* It makes flow of control more complex (and thus harder to test) for 
some implementations.

Thus I'd like to change the return to void. Although that will break 
some code, the breakage will result in a noisy compile-time error that 
is easy to fix by inserting a call to exits() before the call to remove().

Comments?

--Beman

PS: This was precipitated by ticket #1972, but doesn't affect the 
resolution of the remove() issue it raises. That will be fixed for 
1.36.0 regardless.