Several new C library calls have been introduced using blocks. They have _b appended to their names to indicate they are block calls, similar to the way some library functions have _r appended to indicate re-entrant calls. Some of the more useful ones are:
quicksort using a block for a comparator
binary search using a block for a comparator
parallel sort using a block for a comparator
generate pathnames matching a pattern, using a block for an error callback
collect pathnames, using blocks for a path selection and comparison
Cocoa has introduced a large number of block-oriented methods. An easy way to find them all is to search through the framework headers looking for the caret. ...