> Rust knows whether you implemented a trait by hand or merely derived it. In a few cases it can be reasonable for the language to distinguish these cases for built-in traits, since in the former case it knows the derived trait does what is needed
Too late to edit. This should clearly have said,
in the latter case not the former case. In the hand implemented case the compiler has no idea whether your implementation has the desired properties.
Too late to edit. This should clearly have said, in the latter case not the former case. In the hand implemented case the compiler has no idea whether your implementation has the desired properties.