Crate diem_infallible
Source - NonZeroUsize
 - A wrapper around 
std::num::NonZeroUsize to no longer worry about
unwrap() - checked
 - Utility macro for writing secure arithmetic operations in order to avoid
integer overflows.
 
- ArithmeticError
 - Mutex
 - A simple wrapper around the lock() function of a std::sync::Mutex
The only difference is that you don’t need to call unwrap() on it.
 - MutexGuard
 - An RAII implementation of a “scoped lock” of a mutex. When this structure is
dropped (falls out of scope), the lock will be unlocked.
 - RwLock
 - A simple wrapper around the lock() function of a std::sync::RwLock
The only difference is that you don’t need to call unwrap() on it.
 - RwLockReadGuard
 - RAII structure used to release the shared read access of a lock when
dropped.
 - RwLockWriteGuard
 - RAII structure used to release the exclusive write access of a lock when
dropped.
 
- duration_since_epoch
 - Gives the duration since the Unix epoch, notice the expect.