`CheckedAdd` should probably not extend `Add` about num-traits HOT 3 OPEN

I suspect that removing the relationship between CheckedAdd and Add might be a breaking change,

Yes, that is a breaking change, sorry.

I wonder if the real "right" solution also involves getting checked operations into core::ops.

Those traits are all related to built-in language operators, so you can impl Add to get a working + operator on your own types. It's not impossible to think of having core traits for more numeric methods, but there's not any current precedent for that. Most of these num traits were in the standard library before Rust 1.0, and were kicked out to live here instead.

from num-traits.

Most of these num traits were in the standard library before Rust 1.0, and were kicked out to live here instead.

Do you know where I can find any of the history of that decision?

from num-traits.

I found the commit history, but not much discussion. For this particular trait:

• It was removed with its methods transferred to trait Int in rust-lang/rust@e51cc08
• trait Int was deprecated in rust-lang/rust@232424d
• trait Int was removed in rust-lang/rust@eeb9488
  • and backported before 1.0.0 in rust-lang/rust@0372484

from num-traits.