prefer-weakest-access

Prefer the weakest access form required by a value's uses

A borrowed parameter with stronger access than any checked use grants callers unnecessary authority.
Instead, you SHOULD declare the weakest access sufficient for every use of the parameter.

- Category: style
- Level: warning
- Fix: suggestion
- Scope: module

Reported

struct Counter {
    value: int32;
}

function read(counter: &exclusive Counter): int32 {
    return counter.value;
}
Accepted

struct Counter {
    value: int32;
}

function read(counter: &readonly Counter): int32 {
    return counter.value;
}
Prior art

- Clippy · needlesspassbyrefmut

language/linter/src/rules/style/preferweakestaccess.rs:9