Does the C++ 11 standard guarantees that std::atomic<> is implemented as a lock-free operation?

Question

I\'m at a junction, I\'m trying to pick one between mutex-lock-based data structure and lock-free ( and possibly wait-free ) data structure.

While digging a little deepe

Answer 1

The C++ standard makes no guarantee that std::atomic operations are lock-free. However, you can use std::atomic::is_lock_free() to find out if the operation of std::atomic is lock free 29.6.5 [atomics.types.operations.req] paragraph 7:

Returns: True if the object’s operations are lock-free, false otherwise.

If it is not lock-free it will still do the required synchronization but it uses some lock to do so.