(1) explicit set( const Compare& comp = Compare(),
const Allocator& alloc = Allocator() ); (until C++14) set() : set( Compare() ) {}
explicit set( const Compare& comp,
const Allocator& alloc = Allocator() ); (since C++14) explicit set( const Allocator& alloc ); (1) (since C++11) (2) template< class InputIt >
set( InputIt first, InputIt last,
const Compare& comp = Compare(),
const Allocator& alloc = Al