审题 // The procedural macro API uses a type called Span to attach source location // and hygiene information to every token. In order for compiler errors to...

审题 // The previous examples all used an exclusive range, MIN..MAX. Now make it work // for an inclusive range MIN..=MAX that includes the upper range bound!...

审题 // This test case should hopefully be a freebie if all of the previous ones are // passing. This test demonstrates using the seq macro to construct a con...

审题 // So far our macro has repeated the entire loop body. This is not sufficient // for some use cases because there are restrictions on the syntactic posit...

审题 // One of the big things callers will want to do with the sequential indices N // is use them as part of an identifier, like f0 f1 f2 etc. // // Implemen...

审题 // Now construct the generated code! Produce the output TokenStream by repeating // the loop body the correct number of times as specified by the loop bo...

题解 // The macro invocation in the previous test case contained an empty loop body // inside the braces. In reality we want for the macro to accept arbitrary...

审题 // This test looks for a function-like macro with the right name to exist. For // now the test doesn't require any specific code to be generated by the m...

审题 // There are some cases where no heuristic would be sufficient to infer the // right trait bounds based only on the information available during macro //...

审题 // This test case covers one more heuristic that is often worth incorporating // into derive macros that infer trait bounds. Here we look for the use of...

审题 // This test case should not require any code change in your macro if you have // everything up to this point already passing, but is here to demonstrate...

审题 // Some generic types implement Debug even when their type parameters do not. // One example is PhantomData which has this impl: // // impl<T: ?Si...

审题 // Figure out what impl needs to be generated for the Debug impl of Field<T>. // This will involve adding a trait bound to the T type parameter of...

审题 // Look for a field attribute #[debug = "..."] on each field. If present, find a // way to format the field according to the format string given by the c...

审题 // Emit an implementation of std::fmt::Debug for a basic struct with named // fields and no generic type parameters. // // Note that there is no enforced...