The subtraction assignment operator `-=`.

A trait for hashing an arbitrary stream of bytes.

`Request` supports generic, type-driven access to data. Its use is currently restricted to the standard library in cases where trait authors wish to allow trait implementors to share generic information across trait boundaries. The motivating and prototypical use case is `core::error::Error` which would otherwise require a method per concrete type (eg. `std::backtrace::Backtrace` instance that implementors want to expose to users).

The metadata for a `Dyn = dyn SomeTrait` trait object type.

A barrier enables multiple threads to synchronize the beginning of some computation.

The current status of a backtrace, indicating whether it was captured or whether it is empty for some other reason.

An error returned from the `duration_since` and `elapsed` methods on `SystemTime`, used to learn how far in the opposite direction a system time lies.

RAII structure used to release the shared read access of a lock when dropped, which can point to a subfield of the protected data.

The error type for `try_reserve` methods.

A priority queue implemented with a binary heap.