Have a map with keys consisting of different types in C++

Question

I currently am using a map in C++ and have a couple of values that are ints and booleans, though the majority of them are strings. I know in Java I could do something like this:

Answer 1

I don't know of a way you could have a std::map with keys that can be multiple types using the stdlib out of the box.

Boost has a variant type that functions more or less like what you want.

typedef boost::variant key_type;
std::map mapvar

This map will only accept keys that are defined in your chosen key_type, so you could not also use, say, a std::wstring as a key without explicitly declaring it. This would be the advantage of using a variant over any. The latter might happily eat whatever type you send its way, while the former will give you a compile time error.

If you are going to use a boost::variant as your key then you need to read the boost documentation and look into what is involved in constructing variant objects and whether or not they have sorting pre-defined. std::map is built on operator< (unless you template it on some other sorting functor) so you'll need to make sure a working definition for your variant type is provided by either the library or yourself.

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Why do you want to have such a map in the first place?