c++ - Are pointers allowed as keys in ordered STL containers?

Question

There's this other question asking about how comparing pointers is supposed to be interpreted wrt the C++ Std.

So I was wondering what the C++ Std has to say about using pointers as keys in ordered standard library (STL) containers -- i.e. is one allowed to have

std::map<T1*, T2>

and is this due to the specification of std::less or builtin operator <?

Answer 1

Yes, because it uses std::less, which is required to result in a total order even if < doesn't. (< would be allowed to treat different pointers from distinct sequences as equal, which would result in an odd behaviour of map etc if you insert pointers from different sequences).