How to implement the thread_local feature of C++11(TLS) in iOS8

In iOS App development, if we write the following code in Xcode and set the deployment target to 8.0(or below 9.0), an error message will appear:

static thread_local T inst;

The error message is:

Thread-local storage is not supported for the current target

However, my app needs to support users that using iOS 8.0.

Is there a way to break through such restrictions? Or can you provide an alternative to thread_local under iOS8?