Selecting a Collection Class

Be sure to choose your collection class carefully. Using the wrong type can restrict your use of the collection.

Important Avoid using the types in the xtd::collections namespace. The generic and concurrent versions of the collections are recommended because of their greater type safety and other improvements.

Consider the following questions:

• Do you need a sequential list where the element is typically discarded after its value is retrieved?
  • If yes, consider using the xtd::collection::queue class or the std::queue<type_t> generic class if you need first-in, first-out (FIFO) behavior. Consider using the xtd::collection::stack class or the std::stack<type_t> generic class if you need last-in, first-out (LIFO) behavior. For safe access from multiple threads, use the concurrent versions, xtd::collection::concurrent::concurrent_queue<typr_t> and xtd::collection::concurrent::concurrent_stack<type_t>.
  • If not, consider using the other collections.
• Do you need to access the elements in a certain order, such as FIFO, LIFO, or random?
  • The xtd::collection::queue class, as well as the std::queue<type_t> and xtd::collection::concurrent::concurrent_queue<typr_t> generic classes all offer FIFO access. For more information, see When to Use a Thread-Safe Collection.
  • The xtd::collection::stack class, as well as the std::stack<type_t> and xtd::collection::concurrent::concurrent_stack<type_t> generic classes all offer LIFO access. For more information, see When to Use a Thread-Safe Collection.
  • The std::list<type_t> generic class allows sequential access either from the head to the tail, or from the tail to the head.

See also

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• Guides
• Documentation