<!-- Troubleshooting guide: https://rust-analyzer.github.io/manual.html#troubleshooting Forum for questions: https://users.rust-lang.org/c/ide/14 Before submitting, please make sure that you're not running into one of these known issues: 1. on-the-fly diagnostics are mostly unimplemented (`cargo check` diagnostics will be shown when saving a file): #3107 2. attribute proc macros are supported but not enabled by default: #6029 Otherwise please try to provide information which will help us to fix the issue faster. Minimal reproducible examples with few dependencies are especially lovely <3. --> On today's nightly ee4505f:  `T` should be `Sized` implicitly.