tests: add tests for lifetime and const params of opaque types.

Author: eddyb

src/test/ui/type-alias-impl-trait/generic_duplicate_param_use.rs

@@ -1,13 +1,26 @@
-#![feature(type_alias_impl_trait)]
+#![feature(type_alias_impl_trait, const_generics)]
+#![allow(incomplete_features)]
 
 use std::fmt::Debug;
 
 fn main() {}
 
 // test that unused generic parameters are ok
-type Two<T, U> = impl Debug;
+type TwoTys<T, U> = impl Debug;
+type TwoLifetimes<'a, 'b> = impl Debug;
+type TwoConsts<const X: usize, const Y: usize> = impl Debug;
 
-fn one<T: Debug>(t: T) -> Two<T, T> {
+fn one_ty<T: Debug>(t: T) -> TwoTys<T, T> {
+//~^ ERROR non-defining opaque type use in defining scope
+    t
+}
+
+fn one_lifetime<'a>(t: &'a u32) -> TwoLifetimes<'a, 'a> {
+//~^ ERROR non-defining opaque type use in defining scope
+    t
+}
+
+fn one_const<const N: usize>(t: *mut [u8; N]) -> TwoConsts<N, N> {
 //~^ ERROR non-defining opaque type use in defining scope
     t
 }

src/test/ui/type-alias-impl-trait/generic_duplicate_param_use.stderr

@@ -1,14 +1,38 @@
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:10:27
+  --> $DIR/generic_duplicate_param_use.rs:13:30
    |
-LL | fn one<T: Debug>(t: T) -> Two<T, T> {
-   |                           ^^^^^^^^^
+LL | fn one_ty<T: Debug>(t: T) -> TwoTys<T, T> {
+   |                              ^^^^^^^^^^^^
    |
 note: type used multiple times
-  --> $DIR/generic_duplicate_param_use.rs:8:10
+  --> $DIR/generic_duplicate_param_use.rs:9:13
    |
-LL | type Two<T, U> = impl Debug;
-   |          ^  ^
+LL | type TwoTys<T, U> = impl Debug;
+   |             ^  ^
 
-error: aborting due to previous error
+error: non-defining opaque type use in defining scope
+  --> $DIR/generic_duplicate_param_use.rs:18:36
+   |
+LL | fn one_lifetime<'a>(t: &'a u32) -> TwoLifetimes<'a, 'a> {
+   |                                    ^^^^^^^^^^^^^^^^^^^^
+   |
+note: lifetime used multiple times
+  --> $DIR/generic_duplicate_param_use.rs:10:19
+   |
+LL | type TwoLifetimes<'a, 'b> = impl Debug;
+   |                   ^^  ^^
+
+error: non-defining opaque type use in defining scope
+  --> $DIR/generic_duplicate_param_use.rs:23:50
+   |
+LL | fn one_const<const N: usize>(t: *mut [u8; N]) -> TwoConsts<N, N> {
+   |                                                  ^^^^^^^^^^^^^^^
+   |
+note: constant used multiple times
+  --> $DIR/generic_duplicate_param_use.rs:11:22
+   |
+LL | type TwoConsts<const X: usize, const Y: usize> = impl Debug;
+   |                      ^               ^
+
+error: aborting due to 3 previous errors
 

src/test/ui/type-alias-impl-trait/generic_nondefining_use.rs

@@ -1,12 +1,27 @@
-#![feature(type_alias_impl_trait)]
+#![feature(type_alias_impl_trait, const_generics)]
+#![allow(incomplete_features)]
+
+use std::fmt::Debug;
 
 fn main() {}
 
-type Cmp<T> = impl 'static;
-//~^ ERROR: at least one trait must be specified
+type OneTy<T> = impl Debug;
+type OneLifetime<'a> = impl Debug;
+type OneConst<const X: usize> = impl Debug;
 
+// Not defining uses, because they doesn't define *all* possible generics.
 
-// not a defining use, because it doesn't define *all* possible generics
-fn cmp() -> Cmp<u32> { //~ ERROR non-defining opaque type use in defining scope
+fn concrete_ty() -> OneTy<u32> {
+//~^ ERROR non-defining opaque type use in defining scope
     5u32
 }
+
+fn concrete_lifetime() -> OneLifetime<'static> {
+//~^ ERROR non-defining opaque type use in defining scope
+    6u32
+}
+
+fn concrete_const() -> OneConst<{123}> {
+//~^ ERROR non-defining opaque type use in defining scope
+    7u32
+}

src/test/ui/type-alias-impl-trait/generic_nondefining_use.stderr

@@ -1,20 +1,35 @@
-error: at least one trait must be specified
-  --> $DIR/generic_nondefining_use.rs:5:15
+error: non-defining opaque type use in defining scope
+  --> $DIR/generic_nondefining_use.rs:14:21
+   |
+LL | fn concrete_ty() -> OneTy<u32> {
+   |                     ^^^^^^^^^^
+   |
+note: used non-generic type `u32` for generic parameter
+  --> $DIR/generic_nondefining_use.rs:8:12
    |
-LL | type Cmp<T> = impl 'static;
-   |               ^^^^^^^^^^^^
+LL | type OneTy<T> = impl Debug;
+   |            ^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_nondefining_use.rs:10:13
+  --> $DIR/generic_nondefining_use.rs:19:27
    |
-LL | fn cmp() -> Cmp<u32> {
-   |             ^^^^^^^^
+LL | type OneLifetime<'a> = impl Debug;
+   |                  -- cannot use static lifetime; use a bound lifetime instead or remove the lifetime parameter from the opaque type
+...
+LL | fn concrete_lifetime() -> OneLifetime<'static> {
+   |                           ^^^^^^^^^^^^^^^^^^^^
+
+error: non-defining opaque type use in defining scope
+  --> $DIR/generic_nondefining_use.rs:24:24
    |
-note: used non-generic type `u32` for generic parameter
-  --> $DIR/generic_nondefining_use.rs:5:10
+LL | fn concrete_const() -> OneConst<{123}> {
+   |                        ^^^^^^^^^^^^^^^
+   |
+note: used non-generic constant `123usize` for generic parameter
+  --> $DIR/generic_nondefining_use.rs:10:21
    |
-LL | type Cmp<T> = impl 'static;
-   |          ^
+LL | type OneConst<const X: usize> = impl Debug;
+   |                     ^
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors