Erase all the elements in the specified unordered_set s that satisfy the specified predicate predicate. Return the number of elements erased.
Declared in <bslstl_unorderedset.h>
template<
class KEY,
class HASH,
class EQUAL,
class ALLOCATOR,
class PREDICATE>
bsl::unordered_set<KEY, HASH, EQUAL, ALLOCATOR>::size_type
erase_if(
unordered_set<KEY, HASH, EQUAL, ALLOCATOR>& s,
PREDICATE predicate);