Beman Dawes wrote:
The "too similar" problem with overloading predicate functions on directory_iterator is that two very similar calls have different behavior: if ( is_directory( *itr ) ) // uses current status
if ( is_directory( itr ) ) // uses cached status, which may be very stale
That looks like a race-condition trap for unwary users.
I could argue that the second form is less "trappy" for unwary users, actually, because all is_directory( itr ) calls will always yield the same value (and exists(itr) will never yield false for an enumerated item). This comes into play in situations like: void f( itr ) { if( is_directory(itr) ) { g( itr ); } else { h( itr ); } } void g( itr ) { if( is_directory(itr) ) { // ... } else { // ... } }