1 error[E0435]: attempt to use a non-constant value in a constant
4 LL | let foo: usize = 42;
5 | ------- help: consider using `const` instead of `let`: `const foo`
7 | ^^^ non-constant value
9 error: aborting due to previous error
11 For more information about this error, try `rustc --explain E0435`.