This mutable builder can be used when speed is essential
and you can be sure the scope of the mutability cannot escape
in an unsafe way. The intended use is to allocate and call
result in one method without letting a reference to the instance
escape into a closure.
This mutable builder can be used when speed is essential and you can be sure the scope of the mutability cannot escape in an unsafe way. The intended use is to allocate and call result in one method without letting a reference to the instance escape into a closure.