Review/std.experimental.allocator

Description

std.experimental.allocator is a package by Andrei Alexandrescu that standard API for allocators as well as implementation for some of common ones.

What std.experimental.allocator is:

A hookable interface for allocating and releasing memory.
A systematic and hierarchical approach to global allocation, spanning the stack, thread-local storage, and process-level memory.
A collection of quality implementations of typical memory allocation strategies, including free lists, regions, bitmapped blocks, bucketized size-specialized allocators, and more.
A framework for easy assembly and experimentation with custom allocation strategies.
An integration of types within the allocation strategy, allowing concrete allocators to exploit various characteristics of the types they are allocating.

What std.experimental.allocator is not:

An abstraction of lifetime management, e.g. transparently choosing between tracing vs. reference counting.
An abstraction of notions such as "address", "pointer", and "reference".

Formal review is about to start soon