@ais523 in what way is C not TC? just because pointers are fixed-width?

@MartinEnder it's the existence of sizeof; this limits how much data you can store in a pointer (thus limits the number of objects you can have total), and also limits the size of any given object

this means that you can't use C's normal memory allocation routines to store arbitrary amounts of data; it's possible to define the file API in such a way that you can create arbitrarily large files, and the definition does not contradict the standard, but it's very weird and something you don't commonly see on most systems

ah I see

actually, that's not quite true; you can in theory use register variables in recursive functions to store arbitrary amounts of data, but that isn't enough for Turing completeness because you can only access them in the reverse order they were created

that makes C into a push-down automaton, which is the normal fate of languages whose only unbounded storage is one stack