Macro static_mutex_reference 

macro_rules! static_mutex_reference {
    ($type_: ty, $was: expr) => { ... };
}

Create a new static Mutex of something and return a PtrMutex-variant Reference to it.

The documentation shows rrtk::static_mutex_reference and rrtk::reference::static_mutex_reference separately. These are the same macro exported in two different places. These paths point to the same code in RRTK. Rust’s scoping rules for macros are a bit odd, but you should be able to use rrtk::static_mutex_reference and rrtk::reference::static_mutex_reference interchangably.