What is meant by "natural unsigned int"

Question

In the documentation for ldlen and localloc the size type is described as "natural unsigned int". Although I have an idea what is meant (on x64: 64 bit unsigned on x86: 32 bit unsigned) I haven't found any documentation for it.

So is there an "official" documentation about the "natural unsigned int"?

Answer 1

The term natural refers, as you thought, to what is native on the hardware. Although it's not specified explicitly in a glossary, you can make it out from other uses of the word natural in the spec:

The native size types (native int, native unsigned int, and &) are always naturally aligned (4 bytes or 8 bytes, depending on the architecture).

or

autochar indicates a platform-specific representation that is “natural” for the underlying platform