fast collections

This crate need generic_const_exprs feature.

0. I need a complex game system, very fast speed is required!
1. Using String, Box, and Vec is slow due to heap allocation.
2. In that case, let’s use &’str, which is fast even if zero copy modification of the size is impossible. However, it is difficult to manage due to its lifetime.
3. Then there is no Cursor, Vec, or String, but Let’s use [T;N]. However, const generics are difficult to manage
4. If so, let’s use GenericArray. However, it lacks Vec, Cursor, and String types.
5. Then, let’s create a crate that uses typenum rather than const generic without heap allocation and no references.