[vacuity]

I get where you're coming from, but I think it doesn't have to be more complicated than: "Are the two values standard Rust number types? If yes, they do simple multiplication on an asm level. Otherwise, check the relevant Mul implementation."

[softirq]

I disagree, consider a generic that is constrained by std::ops::Add. If you want to write generic functions with this type, you have to contend with types that might do simple addition or do allocations with potential side effects.

[LegionMammal978]

Why would you constrain a generic with ops::Add, if you didn't want to specifically allow for generic implementations of +? If you just want to be generic over built-in integers, it would be as easy as a "trait Integer: Add + Sub + Mul + TryFrom<i32> + ... {}" that's implemented by the standard integer types and sealed off from outside implementations.

[vacuity]

As I understand it, generics are just a particular mechanism for interfacing with multiple types, and C manages without. For the same program, could a programmer ever be more unaware about which types are parameterized and which specific implementations are called in Rust than in C? I don't have much knowledge of C, admittedly, so this isn't a rhetorical question.

[xigoi]

The whole point of generics is that you don’t know and don’t care what the type is.