Prematurely lint against const numbers that would trigger `overflowing_literals` on platforms with smaller `usize`/`isize`s

[paolobarbolini]

What it does

Detect const usize/isize values that correctly build for 64 bit targets but break the build with overflowing_literals on 32 bit or 16 bit targets.

Advantage

• Detect obvious cases in which a program won't build for a different platform
• Detect incorrect uses of usize/isize, and suggest replacing them with u64/i64

Drawbacks

No response

Example

// Example 1
const VALUE: usize = 5000000000;

// Example 2
fn check(val: usize) -> bool {
    val < 5000000000
}

Could be written as:

// Example 1
const VALUE: u64 = 5000000000;

// Example 2
fn check(val: u64) -> bool {
    val < 5000000000
}

[leonardo-m]

Detect obvious cases in which a program won't build for a different platform<

This seems a nice idea. Do we have other similar potential-incompatibily situations that Clippy could help detect?