Clippy misses integer arithmetic error for a specific type

[Chralt98]

Summary

I expected an clippy error when using a specific type, which resolves to be an integer (u128).

Reproducer

I tried this code:

pub type SpecificIntegerType = u128;
pub const NewValue: SpecificIntegerType = 42;

...

let test_arithmetic_integer_error = NewValue + NewValue;

When running with -Dclippy::integer_arithmetic

I expected to see this happen:

error: integer arithmetic detected

Instead, this happened:

No error.

Version

rustc 1.62.0-nightly

Additional Labels

No response

[Alexendoo]

It appears to trigger the lint for https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=5ae8ae28263bb35ccc1987355557aa80

Is there some other context needed?

[Chralt98]

Currently I can't reproduce the error in the rust playground, but I try to describe it with the specific code.

Here is the code, where I would expect a clippy integer arithmetic error. The ValidityBond is a BalanceOf, what you can see here

This BalanceOf type alias references to the following trait type.

type Balance: Balance + MaybeSerializeDeserialize + Debug + MaxEncodedLen;

Where Balance is that:

pub trait Balance:
	AtLeast32BitUnsigned + FullCodec + Copy + Default + Debug + scale_info::TypeInfo
{
}
impl<T: AtLeast32BitUnsigned + FullCodec + Copy + Default + Debug + scale_info::TypeInfo> Balance
	for T
{
}

Reference to the BalanceType is here.

The constant ValidityBond is assigned here. And finally Balance is the u128 type, which you can see here.

[Jarcho]

integer_arithmetic can't lint on generic types as other types could be substituted there.

[Chralt98]

Thank you for your answer. What a pitty!

[Jarcho]

There should be a lint for using any arithmetic operators soonish. Somebody was working on it.

[c410-f3r]

With #9130 merged, this issue can be closed.