# fixed_vec Bounds check indices only once, instead of over and over if the indices will be re-used: ```rust use fixed_vec::{name, FixedVec}; let v = vec![0u32; 10]; let v = name!(v); let mut v = FixedVec::fix(v); // Perform the two index checks here: let index_a = v.check_index(...).unwrap(); let index_b = v.check_index(...).unwrap(); for _ in 0..100 { // These do *not* perform bounds checks! // At compile time, v and index_a must match *v.get_mut(index_a) += 5; *v.get_mut(index_b) += 10; } let v = v.unfix(); // continue using v... ``` See the [concept post](https://github.com/Torrencem/fixed_vec/blob/master/post.md) for more information.