Add note when FnPtr vs. FnDef impl trait
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I encountered an instance where an `FnPtr` implemented a trait, but I was passing an `FnDef`. To the end user, there is really no way to differentiate each of them, but it is necessary to cast to the generic function in order to compile. It is thus useful to suggest `as` in the help note, (even if the Fn output implements the trait).
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…iaskrgr Rollup of 10 pull requests Successful merges: - rust-lang#106046 (Fix mir-opt tests for big-endian platforms) - rust-lang#106470 (tidy: Don't include wasm32 in compiler dependency check) - rust-lang#106566 (Emit a single error for contiguous sequences of unknown tokens) - rust-lang#106644 (Update the wasi-libc used for the wasm32-wasi target) - rust-lang#106665 (Add note when `FnPtr` vs. `FnDef` impl trait) - rust-lang#106752 (Emit a hint for bad call return types due to generic arguments) - rust-lang#106788 (Tweak E0599 and elaborate_predicates) - rust-lang#106831 (Use GitHub yaml templates for ICE, Docs and Diagnostics tickets) - rust-lang#106846 (Improve some comments and names in parser) - rust-lang#106848 (Fix wrong path in triage bot autolabel for wg-trait-solver-refactor) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
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I encountered an instance where an
FnPtrimplemented a trait, but I was passing anFnDef. I was confused for an hour and to examine the source code of the trait's crate's tests in order to understand how to cast it properly (it didn't help that it was behind a reference). To the end user, it might not be immediately obvious that they are different and how to convert from anFnDefto anFnPtr, but it is necessary to cast to the generic function in order to compile. It is thus useful to suggestasin the help note, (even if theFnoutput implements the trait).