c++ - simple unique STL container -
is there unique container such std::list
simple functionality (push
,pop
,clear
, etc.) , not sorted order unlike std::set
, or maybe need extend std::list
, add together own push_unique
method )) ?
the stl supposed provide efficient containers.
a container not allow duplicates needs back upwards fast lookup determine whether value want nowadays in collection or not.
std::set
keeps item sorted in red-black tree, allows o(log(n)) lookup, insertion, , removal.
std::unsorted_set
allows constant-time lookup, insertion, , removal, need provide hash function udt types, need take care of issues such rehashing, cause iterator invalidation, , not have defined order items (not insertion order).
if want utilize simple collection such std::vector
without allowing duplicates, need provide own adapter.
however, still can't figure out why have problems sorted container such std::set
if, say, order doesn't matter you.
c++ stl
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