c++11 std::mutex compiler error in Visual Studio 2012

Question

This a quest about deadlock in C++11 standard.

In the sec3.2.4 of C++ Concurrency in Action, there is an example for preventing multithreads from deadlock. For guys

Answer 1

From this reference:

The mutex class is non-copyable.

A mutex can't be copied or moved.

Answer 2

mutexes are not copyable or assignable, and the std::thread constructor is attempting to make a copy. You can circumvent this by using an std::reference_wrapper via std::ref:

std::thread t1(transfer, std::ref(my_account), std::ref(your_account));

alternatively, you can pass temporary bank_accounts:

std::thread t1(transfer, bank_account(), bank_account());

This will most likely result in the bank_accounts being "moved" rather than copied, although it is also possible that the copy will be avoided via copy elision.

Answer 3

You are making copy of my_account and your_account to std::thread, but std::mutex is neither copyable nor movable.

Try pass by reference:

 std::thread t1(transfer, std::ref(my_account), std::ref(your_account));