Add tests for GAT parameter number and kindness

Author: gavento

src/test/ui/rfc1598-generic-associated-types/parameter_number_and_kind.rs

@@ -0,0 +1,56 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(generic_associated_types)]
+#![feature(associated_type_defaults)]
+
+//FIXME(#44265): "lifetime parameters are not allowed on this type" errors will be addressed in a
+//follow-up PR
+
+//FIXME(#44265): Update expected errors once E110 is resolved, now does not get past `trait Foo`
+
+trait Foo {
+    type A<'a>;
+    type B<'a, 'b>;
+    type C;
+    type D<T>;
+    type E<'a, T>;
+    // Test parameters in default values
+    type FOk<T> = Self::E<'static, T>;
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+    //~| ERROR lifetime parameters are not allowed on this type [E0110]
+    type FErr1 = Self::E<'static, 'static>; // Error
+    //~^ ERROR lifetime parameters are not allowed on this type [E0110]
+    type FErr2<T> = Self::E<'static, T, u32>; // Error
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+    //~| ERROR lifetime parameters are not allowed on this type [E0110]
+}
+
+struct Fooy;
+
+impl Foo for Fooy {
+    type A = u32; // Error: parameter expected
+    type B<'a, T> = Vec<T>; // Error: lifetime param expected
+    type C<'a> = u32; // Error: no param expected
+    type D<'a> = u32; // Error: type param expected
+    type E<T, U> = u32; // Error: lifetime expected as the first param
+}
+
+struct Fooer;
+
+impl Foo for Fooer {
+    type A<T> = u32; // Error: lifetime parameter expected
+    type B<'a> = u32; // Error: another lifetime param expected
+    type C<T> = T; // Error: no param expected
+    type D<'b, T> = u32; // Error: unexpected lifetime param
+    type E<'a, 'b> = u32; // Error: type expected as the second param
+}
+
+fn main() {}

src/test/ui/rfc1598-generic-associated-types/parameter_number_and_kind.stderr

@@ -0,0 +1,34 @@
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/parameter_number_and_kind.rs:26:36
+   |
+LL |     type FOk<T> = Self::E<'static, T>;
+   |                                    ^ type parameter not allowed
+
+error[E0110]: lifetime parameters are not allowed on this type
+  --> $DIR/parameter_number_and_kind.rs:26:27
+   |
+LL |     type FOk<T> = Self::E<'static, T>;
+   |                           ^^^^^^^ lifetime parameter not allowed on this type
+
+error[E0110]: lifetime parameters are not allowed on this type
+  --> $DIR/parameter_number_and_kind.rs:29:26
+   |
+LL |     type FErr1 = Self::E<'static, 'static>; // Error
+   |                          ^^^^^^^ lifetime parameter not allowed on this type
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/parameter_number_and_kind.rs:31:38
+   |
+LL |     type FErr2<T> = Self::E<'static, T, u32>; // Error
+   |                                      ^ type parameter not allowed
+
+error[E0110]: lifetime parameters are not allowed on this type
+  --> $DIR/parameter_number_and_kind.rs:31:29
+   |
+LL |     type FErr2<T> = Self::E<'static, T, u32>; // Error
+   |                             ^^^^^^^ lifetime parameter not allowed on this type
+
+error: aborting due to 5 previous errors
+
+Some errors occurred: E0109, E0110.
+For more information about an error, try `rustc --explain E0109`.