tato tato - 2 months ago 25
C# Question

Mapping between stl C++ and C# containers

Can someone point out a good mapping between the usual C++ STL containers such as vector, list, map, set, multimap... and the C# generic containers?

I'm used to the former ones and somehow I've accustomed myself to express algorithms in terms of those containers. I'm having some hard time finding the C# equivalent to those.

Thank you!

Answer

Here's a rough equivalence:

  1. Dictionary<K,V> <=> unordered_map<K,V>
  2. HashSet<T> <=> unordered_set<T>
  3. List<T> <=> vector<T>
  4. LinkedList<T> <=> list<T>

The .NET BCL (base class library) does not have red-black trees (stl map) or priority queues (make_heap(), push_heap(), pop_heap()).

.NET collections don't use "iterators" the way C++ does. They all implement IEnumerable<T>, and can be iterated over using the "foreach statement". If you want to manually control iteration you can call "GetEnumerator()" on the collection which will return an IEnumerator<T> objet. IEnumerator<T>.MoveNext() is roughly equivalent to "++" on a C++ iterator, and "Current" is roughly equivalent to the pointer-deference operator ("*").

C# does have a language feature called "iterators". They are not the same as "iterator objects" in the STL, however. Instead, they are a language feature that allows for automatic implementation of IEnumerable<T>. See documentation for the yield return and yield break statements for more information.

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