Search results
Results from the WOW.Com Content Network
In the programming language C++, unordered associative containers are a group of class templates in the C++ Standard Library that implement hash table variants. Being templates , they can be used to store arbitrary elements, such as integers or custom classes.
similar to a set, multiset, map, or multimap, respectively, but implemented using a hash table; keys are not ordered, but a hash function must exist for the key type. These types were left out of the C++ standard; similar containers were standardized in C++11, but with different names (unordered_set and unordered_map). Other types of containers ...
This page was last edited on 6 December 2011, at 12:57 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
In C++, the Standard Template Library (STL) provides the set template class, which is typically implemented using a binary search tree (e.g. red–black tree); SGI's STL also provides the hash_set template class, which implements a set using a hash table. C++11 has support for the unordered_set template class, which is implemented using a hash ...
In general, if a set of data structures needs to be included in linked lists, external storage is the best approach. If a set of data structures need to be included in only one linked list, then internal storage is slightly better, unless a generic linked list package using external storage is available.
Key uniqueness: in map and set each key must be unique. multimap and multiset do not have this restriction. Element composition: in map and multimap each element is composed from a key and a mapped value. In set and multiset each element is key; there are no mapped values. Element ordering: elements follow a strict weak ordering [1]
C++11 introduced template aliases, which act like parameterized typedefs. The following code shows the definition of a template alias StrMap. This allows, for example, StrMap<int> to be used as shorthand for std::unordered_map<int,std::string>.
Unordered map can refer to: Unordered associative containers (C++) Hash table; Associative array This page was last edited on 30 ...