In Rust at least, most things have a with_capacity(n) constructor to ensure there's space for n elements (or n bytes, in the case of strings). I suppose there's no getting around the fact that if your collection has no known bounds, you'll have to do bounds checking + potential reallocation in the hot (push) path or risk having your program SIGSEGV.

https://doc.rust-lang.org/std/?search=with_capacity