Is there a Boost.Bimap alternative in c++11?

Is there a usable alternative to Boost's bimap in C++0x?

I would like to avoid Boost, but fully embrace C++11. If necessary, a slimmed down version of Boost's bimap would work for me (I need a constant bimap to switch between enums and corresponding strings) throughout my program. The map will be compile-time constant, so perhaps even two manually maintained maps aren't the optimal solution.

UPDATE: I found this on The Code Project, but it seems licensing may be an issue:

I'm just looking for a clean and easy solution (one header/source file or little extra, as two mirrorred maps are equally fine in my case).

2 Answers

Short answer: no.

Long answer: nope.

It should be noted that C++14's support for transparent comparators eliminates the need for Boost.Bimap 90% of the time^*: when you need to key off of any given property of an object (stored or computed), often a simple, bitwise-comparable unique identifier inherent to/present in the object anyway. With transparent comparators, you can compare an object to any possible value, discriminated only by type, as long as said value can be obtained/computed from an object without mutating it.

_{* a guesstimate, not a statistic}

My feeling is a lot of the work that goes into Boost libraries is making them work with other libraries/STL.

If you don't need that capability, you could just use a class with a std::map<X*, Y*> and std::map<Y*, X*>. Then have methods like the following: add(X,Y), remove(X,Y), get_left(X) and get_right(Y).

If you want to store copies, add(X,Y) could allocate memory, and remove(X,Y) can de-allocate. Also, you can then define a destructor that calls remove(X,Y) on the remainder of the elements.