The vec macros currently there directly call realloc()… that's gonna exclude any custom allocator setups… and the string code uses the vecs :/
The example shown does not use vec from my experimental library.
But yes, I was thinking about making a custom-allocator version of vec.
The allocator interface is defined via these names. Just supply your own realloc. Of course you need to satisfy the constraints of realloc guaranteed to the compiler, or you need to invoke it in freestanding mode.