A small implementation subset of std::map (really, std::unordered_map) that I know doesn't use any static members, and thus is guaranteed threading oblivious.
The basic operations (insert, find, erase, and iterators) are implemented. The map uses hashing, so ordering is not determinate, and changes on re-hashing when the map grows.
#include "imap.h"
imap<std::string, std::string> amap;
amap["1234"] = "5678";
for (auto &p : amap) {
std::cout << p.first << "," << p.second << std::endl;
}
amap.erase(amap.find("1234"));
This is not intended to be the best implementation of a map in the world; instead it is intended to be easy to step through, debug, and verify. For objects with non-trivial copy constructors, it may be less efficient than the standard library, and it is does not make use of move constructors.