wordvec

A compact SmallVec<T>-like container with only align_of::<T>() overhead for small stack-only instances.

WordVec<T, N> stores the length and capacity of a container on the heap. Thus, the heap pointer is always aligned to 2 bytes on most targets, i.e. the least significant bit is always zero. WordVec<T, N> exploits this knowledge to represent small (stack-only) vecs by storing the length as 1 | (length << 1) in the first byte (for little-endian targets), using the least significant bit to distinguish whether it is a heap pointer or a stack length. (As a consequence, N must not exceed 127, which is checked by a const assertion)

Supported platforms

Targets not meeting the following platform requirements will lead to compile error:

• Little-endian only
• align_of::<usize>() must be at least 2 bytes.