Suggest `format!("{x}")` syntax when possible

[digama0]

What it does

Given a use of a format macro, suggest to use the format!("{x}") syntax when applicable.

Lint Name

format_args_capture

Category

pedantic

Advantage

• Code is shorter and more readable
• Increases awareness of the new syntax

Drawbacks

• Increases MSRV for projects that care about that

Example

let x = 2;
println!("{}", x);
println!("{x}", x = x);
println!("{y}", y = x); // untouched because variable name doesn't match

Could be written as:

let x = 2;
println!("{x}");
println!("{x}");
println!("{y}", y = x); // untouched because variable name doesn't match

[jplatte]

Duplicate of #8368.

[giraffate]

Thanks for suggesting a new lint!

I'm closing this because of #8675 (comment).