Bindings and Mutation

Flint has two binding keywords:

• let for immutable bindings,
• mut for mutable bindings.

let threshold = 42
mut count = 0

Why This Matters

Flint wants mutation to be visible at a glance.

That applies beyond local variables. Mutation is also visible in parameter positions and call sites. If something can be changed, Flint tries to say so directly instead of hiding it behind reference syntax or convention.

No Hidden Reference Syntax In Safe Code

Flint does not use & and &mut in normal safe code. The compiler decides when to pass by value and when a by-reference strategy is needed internally.

This keeps the surface language smaller while still preserving ownership and mutation rules.