Following here is an advanced article about the behavior of C++ concerning copy and move operations. A more simple version is provided for a quicker and easier understanding of the best practices. The sum up is, don't declare as deleted a move constructor!
by Howard Hinnant
by Agustín "K-ballo" Bergé
From the article:
Unlike copy operations, which are provided by the compiler if not user declared, move operations can and often are suppressed such that a class might not have one. Furthermore, it is possible for a class to have a —user declared— move operation which is both defined as deleted, and at the same time ignored by overload resolution, as if it didn't exist...