Migrated from https://github.com/rust-lang/rust/issues/38011 ------------------------------------- Default type parameters (e g `struct Foo<A = u32>(A)`) is a language feature, but they are not mentioned in the [language reference](https://doc.rust-lang.org/reference.html#type-parameters). It would be nice if such a reference also mentioned the tricky semantics around how it interacts with inference, as [mentioned here](https://github.com/rust-lang/rust/issues/36980#issuecomment-251726254).