sds (Simple Dynamic Strings from antirez, Redis creator): https://github.com/antirez/sds/blob/master/README.md?plain=1#L33
gb (gb single file libs from gingerBill, Odin language creator): https://github.com/gingerBill/gb/blob/master/gb_string.h#L71
Copy or coincidence?
But of course, we all know that real programmers don't use Pascal and instead prefer to re-invent it with C syntax.
Looking at the git blame, antirez wrote that 12y ago, gingerBill 9y ago. Licenses look both permissible.