What is libc++ and libstdc++

Question

I have a couple of questions.

1) What is libc++ and libstdc++ ?

2) What is the difference between them ?

3) Are they interchangeable ?

4) Is it something a compiler should implement ?

5) When should I use one or another ?

Answer 1

1) What is libc++ and libstdc++ ?

They are implementations of the C++ standard library.

2) What is the difference between them ?

They are entirely different implementations.

3) Are they interchangeable ?

Yes, you should be able to use them interchangeably. (However you can't easily use both in the same program.)

5) When should I use one or another ?

You shouldn't have to worry about that. Your code should work with any standard library implementation.

Answer 2

libstdc++ is the GNU c++ standard library implementation.

libc++ is the LLVM/clang c++ standard library implementation.

Even when compiling with clang, libstdc++ is often used (on Linux).

A main reason libc++ exists is that libstdc++ is GPL and so Apple can't ship it, so you can think of libc++ as the non-GPL libstdc++.