7 files changed, 134 insertions, 0 deletions
diff --git a/tests/ui/mir/field-projection-invariant.rs b/tests/ui/mir/field-projection-invariant.rs
new file mode 100644
index 00000000000..b5d6add043c
--- /dev/null
+++ b/tests/ui/mir/field-projection-invariant.rs
@@ -0,0 +1,24 @@
+// build-pass
+struct Inv<'a>(&'a mut &'a ());
+enum Foo<T> {
+    Bar,
+    Var(T),
+}
+type Supertype = Foo<for<'a> fn(Inv<'a>, Inv<'a>)>;
+
+fn foo(x: Foo<for<'a, 'b> fn(Inv<'a>, Inv<'b>)>) {
+    match x {
+        Supertype::Bar => {}
+        Supertype::Var(x) => {}
+    }
+}
+
+fn foo_nested(x: Foo<Foo<for<'a, 'b> fn(Inv<'a>, Inv<'b>)>>) {
+    match x {
+        Foo::Bar => {}
+        Foo::Var(Supertype::Bar) => {}
+        Foo::Var(Supertype::Var(x)) => {}
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/mir/field-projection-mutating-context.rs b/tests/ui/mir/field-projection-mutating-context.rs
new file mode 100644
index 00000000000..a1002c088dc
--- /dev/null
+++ b/tests/ui/mir/field-projection-mutating-context.rs
@@ -0,0 +1,19 @@
+use std::sync::Mutex;
+
+static GLOBAL: Mutex<&'static str> = Mutex::new("global str");
+
+struct Foo<T>(T); // `T` is covariant.
+
+fn foo() {
+    let mut x: Foo<for<'a> fn(&'a str)> = Foo(|_| ());
+    let Foo(ref mut y): Foo<fn(&'static str)> = x;
+    //~^ ERROR mismatched types
+    *y = |s| *GLOBAL.lock().unwrap() = s;
+    let string = String::from("i am shortlived");
+    (x.0)(&string);
+}
+
+fn main() {
+    foo();
+    println!("{}", GLOBAL.lock().unwrap());
+}
diff --git a/tests/ui/mir/field-projection-mutating-context.stderr b/tests/ui/mir/field-projection-mutating-context.stderr
new file mode 100644
index 00000000000..9b18b3427ad
--- /dev/null
+++ b/tests/ui/mir/field-projection-mutating-context.stderr
@@ -0,0 +1,12 @@
+error[E0308]: mismatched types
+  --> $DIR/field-projection-mutating-context.rs:9:13
+   |
+LL |     let Foo(ref mut y): Foo<fn(&'static str)> = x;
+   |             ^^^^^^^^^ one type is more general than the other
+   |
+   = note: expected fn pointer `for<'a> fn(&'a str)`
+              found fn pointer `fn(&str)`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/mir/field-projection-mutating-context2.rs b/tests/ui/mir/field-projection-mutating-context2.rs
new file mode 100644
index 00000000000..dd9c44a16d3
--- /dev/null
+++ b/tests/ui/mir/field-projection-mutating-context2.rs
@@ -0,0 +1,17 @@
+use std::sync::Mutex;
+
+static GLOBAL: Mutex<&'static str> = Mutex::new("global str");
+
+struct Foo<T>(T); // `T` is covariant.
+
+fn foo<'a>(mut x: Foo<fn(&'a str)>, string: &'a str) {
+    let Foo(ref mut y): Foo<fn(&'static str)> = x;
+    //~^ ERROR lifetime may not live long enough
+    *y = |s| *GLOBAL.lock().unwrap() = s;
+    (x.0)(&string);
+}
+
+fn main() {
+    foo(Foo(|_| ()), &String::from("i am shortlived"));
+    println!("{}", GLOBAL.lock().unwrap());
+}
diff --git a/tests/ui/mir/field-projection-mutating-context2.stderr b/tests/ui/mir/field-projection-mutating-context2.stderr
new file mode 100644
index 00000000000..a7b66fe10ce
--- /dev/null
+++ b/tests/ui/mir/field-projection-mutating-context2.stderr
@@ -0,0 +1,10 @@
+error: lifetime may not live long enough
+  --> $DIR/field-projection-mutating-context2.rs:8:25
+   |
+LL | fn foo<'a>(mut x: Foo<fn(&'a str)>, string: &'a str) {
+   |        -- lifetime `'a` defined here
+LL |     let Foo(ref mut y): Foo<fn(&'static str)> = x;
+   |                         ^^^^^^^^^^^^^^^^^^^^^ type annotation requires that `'a` must outlive `'static`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/mir/field-ty-ascription-enums.rs b/tests/ui/mir/field-ty-ascription-enums.rs
new file mode 100644
index 00000000000..179af617090
--- /dev/null
+++ b/tests/ui/mir/field-ty-ascription-enums.rs
@@ -0,0 +1,15 @@
+// build-pass
+
+enum Foo<T> {
+    Var(T),
+} // `T` is covariant.
+
+fn foo<'b>(x: Foo<for<'a> fn(&'a ())>) {
+    let Foo::Var(x): Foo<fn(&'b ())> = x;
+}
+
+fn foo_nested<'b>(x: Foo<Foo<for<'a> fn(&'a ())>>) {
+    let Foo::Var(Foo::Var(x)): Foo<Foo<fn(&'b ())>> = x;
+}
+
+fn main() {}
diff --git a/tests/ui/mir/field-ty-ascription.rs b/tests/ui/mir/field-ty-ascription.rs
new file mode 100644
index 00000000000..178c7916bc5
--- /dev/null
+++ b/tests/ui/mir/field-ty-ascription.rs
@@ -0,0 +1,37 @@
+// build-pass
+
+struct Foo<T>(T); // `T` is covariant.
+
+struct Bar<T> {
+    x: T,
+} // `T` is covariant.
+
+fn bar<'b>(x: Bar<for<'a> fn(&'a ())>) {
+    let Bar { x }: Bar<fn(&'b ())> = x;
+}
+
+fn bar_nested<'b>(x: Bar<Bar<for<'a> fn(&'a ())>>) {
+    let Bar { x: Bar { x } }: Bar<Bar<fn(&'b ())>> = x;
+}
+
+fn bar_foo_nested<'b>(x: Bar<Foo<for<'a> fn(&'a ())>>) {
+    let Bar { x: Foo ( x ) }: Bar<Foo<fn(&'b ())>> = x;
+}
+
+fn foo<'b>(x: Foo<for<'a> fn(&'a ())>) {
+    let Foo(y): Foo<fn(&'b ())> = x;
+}
+
+fn foo_nested<'b>(x: Foo<Foo<for<'a> fn(&'a ())>>) {
+    let Foo(Foo(y)): Foo<Foo<fn(&'b ())>> = x;
+}
+
+fn tuple<'b>(x: (u32, for<'a> fn(&'a ()))) {
+    let (_, y): (u32, fn(&'b ())) = x;
+}
+
+fn tuple_nested<'b>(x: (u32, (u32, for<'a> fn(&'a ())))) {
+    let (_, (_, y)): (u32, (u32, fn(&'b ()))) = x;
+}
+
+fn main() {}