Expand impl type parameter suggestion tests

Author: mibac138

src/test/ui/missing/missing-items/missing-type-parameter2.rs

@@ -0,0 +1,18 @@
+#![allow(incomplete_features)]
+#![feature(const_generics_defaults)]
+
+struct X<const N: u8>();
+
+impl X<N> {}
+//~^ ERROR cannot find type `N` in this scope
+//~| ERROR unresolved item provided when a constant was expected
+impl<T, const A: u8 = 2> X<N> {}
+//~^ ERROR cannot find type `N` in this scope
+//~| ERROR defaults for const parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions
+//~| ERROR unresolved item provided when a constant was expected
+
+fn bar<const N: u8>(a: A) {}
+//~^ ERROR cannot find type `A` in this scope
+
+fn main() {
+}

src/test/ui/missing/missing-items/missing-type-parameter2.stderr

@@ -0,0 +1,85 @@
+error[E0412]: cannot find type `N` in this scope
+  --> $DIR/missing-type-parameter2.rs:6:8
+   |
+LL | struct X<const N: u8>();
+   | ------------------------ similarly named struct `X` defined here
+LL | 
+LL | impl X<N> {}
+   |        ^
+   |
+help: a struct with a similar name exists
+   |
+LL | impl X<X> {}
+   |        ^
+help: you might be missing a type parameter
+   |
+LL | impl<N> X<N> {}
+   |     ^^^
+
+error[E0412]: cannot find type `N` in this scope
+  --> $DIR/missing-type-parameter2.rs:9:28
+   |
+LL | impl<T, const A: u8 = 2> X<N> {}
+   |      -                     ^
+   |      |
+   |      similarly named type parameter `T` defined here
+   |
+help: a type parameter with a similar name exists
+   |
+LL | impl<T, const A: u8 = 2> X<T> {}
+   |                            ^
+help: you might be missing a type parameter
+   |
+LL | impl<T, const A, N: u8 = 2> X<N> {}
+   |                ^^^
+
+error[E0412]: cannot find type `A` in this scope
+  --> $DIR/missing-type-parameter2.rs:14:24
+   |
+LL | struct X<const N: u8>();
+   | ------------------------ similarly named struct `X` defined here
+...
+LL | fn bar<const N: u8>(a: A) {}
+   |                        ^
+   |
+help: a struct with a similar name exists
+   |
+LL | fn bar<const N: u8>(a: X) {}
+   |                        ^
+help: you might be missing a type parameter
+   |
+LL | fn bar<const N, A: u8>(a: A) {}
+   |               ^^^
+
+error[E0747]: unresolved item provided when a constant was expected
+  --> $DIR/missing-type-parameter2.rs:6:8
+   |
+LL | impl X<N> {}
+   |        ^
+   |
+help: if this generic argument was intended as a const parameter, surround it with braces
+   |
+LL | impl X<{ N }> {}
+   |        ^   ^
+
+error: defaults for const parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions
+  --> $DIR/missing-type-parameter2.rs:9:15
+   |
+LL | impl<T, const A: u8 = 2> X<N> {}
+   |               ^
+
+error[E0747]: unresolved item provided when a constant was expected
+  --> $DIR/missing-type-parameter2.rs:9:28
+   |
+LL | impl<T, const A: u8 = 2> X<N> {}
+   |                            ^
+   |
+help: if this generic argument was intended as a const parameter, surround it with braces
+   |
+LL | impl<T, const A: u8 = 2> X<{ N }> {}
+   |                            ^   ^
+
+error: aborting due to 6 previous errors
+
+Some errors have detailed explanations: E0412, E0747.
+For more information about an error, try `rustc --explain E0412`.