Rollup merge of rust-lang#87383 - Alexendoo:impl_trait_in_bindings-te…

…sts, r=oli-obk

Add regression tests for the impl_trait_in_bindings ICEs

Closes rust-lang#54600, closes rust-lang#54840, closes rust-lang#58504, closes rust-lang#58956, closes rust-lang#70971, closes rust-lang#79099, closes rust-lang#84919, closes rust-lang#86201, closes rust-lang#86642, closes rust-lang#87295

r? `@oli-obk`

src/test/ui/impl-trait/issues/issue-54600.rs

@@ -0,0 +1,7 @@
+use std::fmt::Debug;
+
+fn main() {
+    let x: Option<impl Debug> = Some(44_u32);
+    //~^ `impl Trait` not allowed outside of function and method return types
+    println!("{:?}", x);
+}

src/test/ui/impl-trait/issues/issue-54600.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-54600.rs:4:19
+   |
+LL |     let x: Option<impl Debug> = Some(44_u32);
+   |                   ^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-54840.rs

@@ -0,0 +1,7 @@
+use std::ops::Add;
+
+fn main() {
+    let i: i32 = 0;
+    let j: &impl Add = &i;
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-54840.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-54840.rs:5:13
+   |
+LL |     let j: &impl Add = &i;
+   |             ^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-58504.rs

@@ -0,0 +1,12 @@
+#![feature(generators, generator_trait, never_type)]
+
+use std::ops::Generator;
+
+fn mk_gen() -> impl Generator<Return=!, Yield=()> {
+    || { loop { yield; } }
+}
+
+fn main() {
+    let gens: [impl Generator<Return=!, Yield=()>;2] = [ mk_gen(), mk_gen() ];
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-58504.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-58504.rs:10:16
+   |
+LL |     let gens: [impl Generator<Return=!, Yield=()>;2] = [ mk_gen(), mk_gen() ];
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-58956.rs

@@ -0,0 +1,14 @@
+trait Lam {}
+
+pub struct B;
+impl Lam for B {}
+pub struct Wrap<T>(T);
+
+const _A: impl Lam = {
+    //~^ `impl Trait` not allowed outside of function and method return types
+    let x: Wrap<impl Lam> = Wrap(B);
+    //~^ `impl Trait` not allowed outside of function and method return types
+    x.0
+};
+
+fn main() {}

src/test/ui/impl-trait/issues/issue-58956.stderr

@@ -0,0 +1,15 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-58956.rs:7:11
+   |
+LL | const _A: impl Lam = {
+   |           ^^^^^^^^
+
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-58956.rs:9:17
+   |
+LL |     let x: Wrap<impl Lam> = Wrap(B);
+   |                 ^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-70971.rs

@@ -0,0 +1,4 @@
+fn main() {
+    let x : (impl Copy,) = (true,);
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-70971.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-70971.rs:2:14
+   |
+LL |     let x : (impl Copy,) = (true,);
+   |              ^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-79099.rs

@@ -0,0 +1,10 @@
+struct Bug {
+    V1: [(); {
+        let f: impl core::future::Future<Output = u8> = async { 1 };
+        //~^ `impl Trait` not allowed outside of function and method return types
+        //~| expected identifier
+        1
+    }],
+}
+
+fn main() {}

src/test/ui/impl-trait/issues/issue-79099.stderr

@@ -0,0 +1,20 @@
+error: expected identifier, found `1`
+  --> $DIR/issue-79099.rs:3:65
+   |
+LL |         let f: impl core::future::Future<Output = u8> = async { 1 };
+   |                                                         -----   ^ expected identifier
+   |                                                         |
+   |                                                         `async` blocks are only allowed in Rust 2018 or later
+   |
+   = help: set `edition = "2018"` in `Cargo.toml`
+   = note: for more on editions, read https://doc.rust-lang.org/edition-guide
+
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-79099.rs:3:16
+   |
+LL |         let f: impl core::future::Future<Output = u8> = async { 1 };
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-84919.rs

@@ -0,0 +1,9 @@
+trait Trait {}
+impl Trait for () {}
+
+fn foo<'a: 'a>() {
+    let _x: impl Trait = ();
+    //~^ `impl Trait` not allowed outside of function and method return types
+}
+
+fn main() {}

src/test/ui/impl-trait/issues/issue-84919.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-84919.rs:5:13
+   |
+LL |     let _x: impl Trait = ();
+   |             ^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-86201.rs

@@ -0,0 +1,13 @@
+#![feature(unboxed_closures)]
+#![feature(min_type_alias_impl_trait)]
+
+type FunType = impl Fn<()>;
+//~^ could not find defining uses
+static STATIC_FN: FunType = some_fn;
+//~^ mismatched types
+
+fn some_fn() {}
+
+fn main() {
+    let _: <FunType as FnOnce<()>>::Output = STATIC_FN();
+}

src/test/ui/impl-trait/issues/issue-86201.stderr

@@ -0,0 +1,21 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-86201.rs:6:29
+   |
+LL | type FunType = impl Fn<()>;
+   |                ----------- the expected opaque type
+LL |
+LL | static STATIC_FN: FunType = some_fn;
+   |                             ^^^^^^^ expected opaque type, found fn item
+   |
+   = note: expected opaque type `impl Fn<()>`
+                  found fn item `fn() {some_fn}`
+
+error: could not find defining uses
+  --> $DIR/issue-86201.rs:4:16
+   |
+LL | type FunType = impl Fn<()>;
+   |                ^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/impl-trait/issues/issue-86642.rs

@@ -0,0 +1,8 @@
+static x: impl Fn(&str) -> Result<&str, ()> = move |source| {
+    //~^ `impl Trait` not allowed outside of function and method return types
+    let res = (move |source| Ok(source))(source);
+    let res = res.or((move |source| Ok(source))(source));
+    res
+};
+
+fn main() {}

src/test/ui/impl-trait/issues/issue-86642.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-86642.rs:1:11
+   |
+LL | static x: impl Fn(&str) -> Result<&str, ()> = move |source| {
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-87295.rs

@@ -0,0 +1,18 @@
+trait Trait {
+    type Output;
+}
+impl Trait for () {
+    type Output = i32;
+}
+
+struct Struct<F>(F);
+impl<F> Struct<F> {
+    pub fn new(_: F) -> Self {
+        todo!()
+    }
+}
+
+fn main() {
+    let _do_not_waste: Struct<impl Trait<Output = i32>> = Struct::new(());
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-87295.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-87295.rs:16:31
+   |
+LL |     let _do_not_waste: Struct<impl Trait<Output = i32>> = Struct::new(());
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.