Move /src/test to /tests

28 files changed, 870 insertions, 0 deletions

diff --git a/tests/ui/dst/dst-bad-assign-2.rs b/tests/ui/dst/dst-bad-assign-2.rs
new file mode 100644
index 00000000000..7ba31bf2e51
--- /dev/null
+++ b/tests/ui/dst/dst-bad-assign-2.rs
@@ -0,0 +1,38 @@
+// Forbid assignment into a dynamically sized type.
+
+struct Fat<T: ?Sized> {
+    f1: isize,
+    f2: &'static str,
+    ptr: T
+}
+
+#[derive(PartialEq,Eq)]
+struct Bar;
+
+#[derive(PartialEq,Eq)]
+struct Bar1 {
+    f: isize
+}
+
+trait ToBar {
+    fn to_bar(&self) -> Bar;
+    fn to_val(&self) -> isize;
+}
+
+impl ToBar for Bar1 {
+    fn to_bar(&self) -> Bar {
+        Bar
+    }
+    fn to_val(&self) -> isize {
+        self.f
+    }
+}
+
+pub fn main() {
+    // Assignment.
+    let f5: &mut Fat<dyn ToBar> = &mut Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
+    let z: Box<dyn ToBar> = Box::new(Bar1 {f: 36});
+    f5.ptr = *z;
+    //~^ ERROR the size for values of type
+
+}
diff --git a/tests/ui/dst/dst-bad-assign-2.stderr b/tests/ui/dst/dst-bad-assign-2.stderr
new file mode 100644
index 00000000000..6c9e2971c6d
--- /dev/null
+++ b/tests/ui/dst/dst-bad-assign-2.stderr
@@ -0,0 +1,12 @@
+error[E0277]: the size for values of type `dyn ToBar` cannot be known at compilation time
+  --> $DIR/dst-bad-assign-2.rs:35:5
+   |
+LL |     f5.ptr = *z;
+   |     ^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `dyn ToBar`
+   = note: the left-hand-side of an assignment must have a statically known size
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-bad-assign-3.rs b/tests/ui/dst/dst-bad-assign-3.rs
new file mode 100644
index 00000000000..d05b3937c99
--- /dev/null
+++ b/tests/ui/dst/dst-bad-assign-3.rs
@@ -0,0 +1,39 @@
+// Forbid assignment into a dynamically sized type.
+
+#![feature(unsized_tuple_coercion)]
+
+type Fat<T> = (isize, &'static str, T);
+
+#[derive(PartialEq,Eq)]
+struct Bar;
+
+#[derive(PartialEq,Eq)]
+struct Bar1 {
+    f: isize
+}
+
+trait ToBar {
+    fn to_bar(&self) -> Bar;
+    fn to_val(&self) -> isize;
+}
+
+impl ToBar for Bar1 {
+    fn to_bar(&self) -> Bar {
+        Bar
+    }
+    fn to_val(&self) -> isize {
+        self.f
+    }
+}
+
+pub fn main() {
+    // Assignment.
+    let f5: &mut Fat<dyn ToBar> = &mut (5, "some str", Bar1 {f :42});
+    let z: Box<dyn ToBar> = Box::new(Bar1 {f: 36});
+    f5.2 = Bar1 {f: 36};
+    //~^ ERROR mismatched types
+    //~| expected trait object `dyn ToBar`, found struct `Bar1`
+    //~| expected trait object `dyn ToBar`
+    //~| found struct `Bar1`
+    //~| ERROR the size for values of type
+}
diff --git a/tests/ui/dst/dst-bad-assign-3.stderr b/tests/ui/dst/dst-bad-assign-3.stderr
new file mode 100644
index 00000000000..b326dbbbc14
--- /dev/null
+++ b/tests/ui/dst/dst-bad-assign-3.stderr
@@ -0,0 +1,24 @@
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-assign-3.rs:33:12
+   |
+LL |     f5.2 = Bar1 {f: 36};
+   |     ----   ^^^^^^^^^^^^ expected trait object `dyn ToBar`, found struct `Bar1`
+   |     |
+   |     expected due to the type of this binding
+   |
+   = note: expected trait object `dyn ToBar`
+                    found struct `Bar1`
+
+error[E0277]: the size for values of type `dyn ToBar` cannot be known at compilation time
+  --> $DIR/dst-bad-assign-3.rs:33:5
+   |
+LL |     f5.2 = Bar1 {f: 36};
+   |     ^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `dyn ToBar`
+   = note: the left-hand-side of an assignment must have a statically known size
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-bad-assign.rs b/tests/ui/dst/dst-bad-assign.rs
new file mode 100644
index 00000000000..496e01ae005
--- /dev/null
+++ b/tests/ui/dst/dst-bad-assign.rs
@@ -0,0 +1,41 @@
+// Forbid assignment into a dynamically sized type.
+
+struct Fat<T: ?Sized> {
+    f1: isize,
+    f2: &'static str,
+    ptr: T
+}
+
+#[derive(PartialEq,Eq)]
+struct Bar;
+
+#[derive(PartialEq,Eq)]
+struct Bar1 {
+    f: isize
+}
+
+trait ToBar {
+    fn to_bar(&self) -> Bar;
+    fn to_val(&self) -> isize;
+}
+
+impl ToBar for Bar1 {
+    fn to_bar(&self) -> Bar {
+        Bar
+    }
+    fn to_val(&self) -> isize {
+        self.f
+    }
+}
+
+pub fn main() {
+    // Assignment.
+    let f5: &mut Fat<dyn ToBar> = &mut Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
+    let z: Box<dyn ToBar> = Box::new(Bar1 {f: 36});
+    f5.ptr = Bar1 {f: 36};
+    //~^ ERROR mismatched types
+    //~| expected trait object `dyn ToBar`, found struct `Bar1`
+    //~| expected trait object `dyn ToBar`
+    //~| found struct `Bar1`
+    //~| ERROR the size for values of type
+}
diff --git a/tests/ui/dst/dst-bad-assign.stderr b/tests/ui/dst/dst-bad-assign.stderr
new file mode 100644
index 00000000000..614f2138751
--- /dev/null
+++ b/tests/ui/dst/dst-bad-assign.stderr
@@ -0,0 +1,24 @@
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-assign.rs:35:14
+   |
+LL |     f5.ptr = Bar1 {f: 36};
+   |     ------   ^^^^^^^^^^^^ expected trait object `dyn ToBar`, found struct `Bar1`
+   |     |
+   |     expected due to the type of this binding
+   |
+   = note: expected trait object `dyn ToBar`
+                    found struct `Bar1`
+
+error[E0277]: the size for values of type `dyn ToBar` cannot be known at compilation time
+  --> $DIR/dst-bad-assign.rs:35:5
+   |
+LL |     f5.ptr = Bar1 {f: 36};
+   |     ^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `dyn ToBar`
+   = note: the left-hand-side of an assignment must have a statically known size
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-bad-coerce1.rs b/tests/ui/dst/dst-bad-coerce1.rs
new file mode 100644
index 00000000000..7ef237e39e3
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce1.rs
@@ -0,0 +1,36 @@
+// Attempt to change the type as well as unsizing.
+
+#![feature(unsized_tuple_coercion)]
+
+struct Fat<T: ?Sized> {
+    ptr: T
+}
+
+struct Foo;
+trait Bar { fn bar(&self) {} }
+
+pub fn main() {
+    // With a vec of isize.
+    let f1 = Fat { ptr: [1, 2, 3] };
+    let f2: &Fat<[isize; 3]> = &f1;
+    let f3: &Fat<[usize]> = f2;
+    //~^ ERROR mismatched types
+
+    // With a trait.
+    let f1 = Fat { ptr: Foo };
+    let f2: &Fat<Foo> = &f1;
+    let f3: &Fat<dyn Bar> = f2;
+    //~^ ERROR `Foo: Bar` is not satisfied
+
+    // Tuple with a vec of isize.
+    let f1 = ([1, 2, 3],);
+    let f2: &([isize; 3],) = &f1;
+    let f3: &([usize],) = f2;
+    //~^ ERROR mismatched types
+
+    // Tuple with a trait.
+    let f1 = (Foo,);
+    let f2: &(Foo,) = &f1;
+    let f3: &(dyn Bar,) = f2;
+    //~^ ERROR `Foo: Bar` is not satisfied
+}
diff --git a/tests/ui/dst/dst-bad-coerce1.stderr b/tests/ui/dst/dst-bad-coerce1.stderr
new file mode 100644
index 00000000000..594acff853a
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce1.stderr
@@ -0,0 +1,42 @@
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce1.rs:16:29
+   |
+LL |     let f3: &Fat<[usize]> = f2;
+   |             -------------   ^^ expected slice `[usize]`, found array `[isize; 3]`
+   |             |
+   |             expected due to this
+   |
+   = note: expected reference `&Fat<[usize]>`
+              found reference `&Fat<[isize; 3]>`
+
+error[E0277]: the trait bound `Foo: Bar` is not satisfied
+  --> $DIR/dst-bad-coerce1.rs:22:29
+   |
+LL |     let f3: &Fat<dyn Bar> = f2;
+   |                             ^^ the trait `Bar` is not implemented for `Foo`
+   |
+   = note: required for the cast from `Foo` to the object type `dyn Bar`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce1.rs:28:27
+   |
+LL |     let f3: &([usize],) = f2;
+   |             -----------   ^^ expected slice `[usize]`, found array `[isize; 3]`
+   |             |
+   |             expected due to this
+   |
+   = note: expected reference `&([usize],)`
+              found reference `&([isize; 3],)`
+
+error[E0277]: the trait bound `Foo: Bar` is not satisfied
+  --> $DIR/dst-bad-coerce1.rs:34:27
+   |
+LL |     let f3: &(dyn Bar,) = f2;
+   |                           ^^ the trait `Bar` is not implemented for `Foo`
+   |
+   = note: required for the cast from `Foo` to the object type `dyn Bar`
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-bad-coerce2.rs b/tests/ui/dst/dst-bad-coerce2.rs
new file mode 100644
index 00000000000..e7ce20b8958
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce2.rs
@@ -0,0 +1,31 @@
+// Attempt to change the mutability as well as unsizing.
+
+struct Fat<T: ?Sized> {
+    ptr: T
+}
+
+struct Foo;
+trait Bar {}
+impl Bar for Foo {}
+
+pub fn main() {
+    // With a vec of ints.
+    let f1 = Fat { ptr: [1, 2, 3] };
+    let f2: &Fat<[isize; 3]> = &f1;
+    let f3: &mut Fat<[isize]> = f2; //~ ERROR mismatched types
+
+    // With a trait.
+    let f1 = Fat { ptr: Foo };
+    let f2: &Fat<Foo> = &f1;
+    let f3: &mut Fat<dyn Bar> = f2; //~ ERROR mismatched types
+
+    // Tuple with a vec of ints.
+    let f1 = ([1, 2, 3],);
+    let f2: &([isize; 3],) = &f1;
+    let f3: &mut ([isize],) = f2; //~ ERROR mismatched types
+
+    // Tuple with a trait.
+    let f1 = (Foo,);
+    let f2: &(Foo,) = &f1;
+    let f3: &mut (dyn Bar,) = f2; //~ ERROR mismatched types
+}
diff --git a/tests/ui/dst/dst-bad-coerce2.stderr b/tests/ui/dst/dst-bad-coerce2.stderr
new file mode 100644
index 00000000000..3ded96cfb61
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce2.stderr
@@ -0,0 +1,47 @@
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce2.rs:15:33
+   |
+LL |     let f3: &mut Fat<[isize]> = f2;
+   |             -----------------   ^^ types differ in mutability
+   |             |
+   |             expected due to this
+   |
+   = note: expected mutable reference `&mut Fat<[isize]>`
+                      found reference `&Fat<[isize; 3]>`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce2.rs:20:33
+   |
+LL |     let f3: &mut Fat<dyn Bar> = f2;
+   |             -----------------   ^^ types differ in mutability
+   |             |
+   |             expected due to this
+   |
+   = note: expected mutable reference `&mut Fat<dyn Bar>`
+                      found reference `&Fat<Foo>`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce2.rs:25:31
+   |
+LL |     let f3: &mut ([isize],) = f2;
+   |             ---------------   ^^ types differ in mutability
+   |             |
+   |             expected due to this
+   |
+   = note: expected mutable reference `&mut ([isize],)`
+                      found reference `&([isize; 3],)`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce2.rs:30:31
+   |
+LL |     let f3: &mut (dyn Bar,) = f2;
+   |             ---------------   ^^ types differ in mutability
+   |             |
+   |             expected due to this
+   |
+   = note: expected mutable reference `&mut (dyn Bar,)`
+                      found reference `&(Foo,)`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/dst/dst-bad-coerce3.rs b/tests/ui/dst/dst-bad-coerce3.rs
new file mode 100644
index 00000000000..fd5ee3b57bb
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce3.rs
@@ -0,0 +1,37 @@
+// Attempt to extend the lifetime as well as unsizing.
+
+#![feature(unsized_tuple_coercion)]
+
+struct Fat<T: ?Sized> {
+    ptr: T
+}
+
+struct Foo;
+trait Bar { fn bar(&self) {} }
+impl Bar for Foo {}
+
+fn baz<'a>() {
+    // With a vec of ints.
+    let f1 = Fat { ptr: [1, 2, 3] };
+    let f2: &Fat<[isize; 3]> = &f1; //~ ERROR `f1` does not live long enough
+    let f3: &'a Fat<[isize]> = f2;
+
+    // With a trait.
+    let f1 = Fat { ptr: Foo };
+    let f2: &Fat<Foo> = &f1; //~ ERROR `f1` does not live long enough
+    let f3: &'a Fat<dyn Bar> = f2;
+
+    // Tuple with a vec of ints.
+    let f1 = ([1, 2, 3],);
+    let f2: &([isize; 3],) = &f1; //~ ERROR `f1` does not live long enough
+    let f3: &'a ([isize],) = f2;
+
+    // Tuple with a trait.
+    let f1 = (Foo,);
+    let f2: &(Foo,) = &f1; //~ ERROR `f1` does not live long enough
+    let f3: &'a (dyn Bar,) = f2;
+}
+
+pub fn main() {
+    baz();
+}
diff --git a/tests/ui/dst/dst-bad-coerce3.stderr b/tests/ui/dst/dst-bad-coerce3.stderr
new file mode 100644
index 00000000000..957e98bbeee
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce3.stderr
@@ -0,0 +1,58 @@
+error[E0597]: `f1` does not live long enough
+  --> $DIR/dst-bad-coerce3.rs:16:32
+   |
+LL | fn baz<'a>() {
+   |        -- lifetime `'a` defined here
+...
+LL |     let f2: &Fat<[isize; 3]> = &f1;
+   |                                ^^^ borrowed value does not live long enough
+LL |     let f3: &'a Fat<[isize]> = f2;
+   |             ---------------- type annotation requires that `f1` is borrowed for `'a`
+...
+LL | }
+   | - `f1` dropped here while still borrowed
+
+error[E0597]: `f1` does not live long enough
+  --> $DIR/dst-bad-coerce3.rs:21:25
+   |
+LL | fn baz<'a>() {
+   |        -- lifetime `'a` defined here
+...
+LL |     let f2: &Fat<Foo> = &f1;
+   |                         ^^^ borrowed value does not live long enough
+LL |     let f3: &'a Fat<dyn Bar> = f2;
+   |             ---------------- type annotation requires that `f1` is borrowed for `'a`
+...
+LL | }
+   | - `f1` dropped here while still borrowed
+
+error[E0597]: `f1` does not live long enough
+  --> $DIR/dst-bad-coerce3.rs:26:30
+   |
+LL | fn baz<'a>() {
+   |        -- lifetime `'a` defined here
+...
+LL |     let f2: &([isize; 3],) = &f1;
+   |                              ^^^ borrowed value does not live long enough
+LL |     let f3: &'a ([isize],) = f2;
+   |             -------------- type annotation requires that `f1` is borrowed for `'a`
+...
+LL | }
+   | - `f1` dropped here while still borrowed
+
+error[E0597]: `f1` does not live long enough
+  --> $DIR/dst-bad-coerce3.rs:31:23
+   |
+LL | fn baz<'a>() {
+   |        -- lifetime `'a` defined here
+...
+LL |     let f2: &(Foo,) = &f1;
+   |                       ^^^ borrowed value does not live long enough
+LL |     let f3: &'a (dyn Bar,) = f2;
+   |             -------------- type annotation requires that `f1` is borrowed for `'a`
+LL | }
+   | - `f1` dropped here while still borrowed
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/tests/ui/dst/dst-bad-coerce4.rs b/tests/ui/dst/dst-bad-coerce4.rs
new file mode 100644
index 00000000000..f63da60d281
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce4.rs
@@ -0,0 +1,25 @@
+// Attempt to coerce from unsized to sized.
+
+#![feature(unsized_tuple_coercion)]
+
+struct Fat<T: ?Sized> {
+    ptr: T
+}
+
+pub fn main() {
+    // With a vec of isizes.
+    let f1: &Fat<[isize]> = &Fat { ptr: [1, 2, 3] };
+    let f2: &Fat<[isize; 3]> = f1;
+    //~^ ERROR mismatched types
+    //~| expected array `[isize; 3]`, found slice `[isize]`
+    //~| expected reference `&Fat<[isize; 3]>`
+    //~| found reference `&Fat<[isize]>`
+
+    // Tuple with a vec of isizes.
+    let f1: &([isize],) = &([1, 2, 3],);
+    let f2: &([isize; 3],) = f1;
+    //~^ ERROR mismatched types
+    //~| expected array `[isize; 3]`, found slice `[isize]`
+    //~| expected reference `&([isize; 3],)`
+    //~| found reference `&([isize],)`
+}
diff --git a/tests/ui/dst/dst-bad-coerce4.stderr b/tests/ui/dst/dst-bad-coerce4.stderr
new file mode 100644
index 00000000000..4c9954f3520
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coerce4.stderr
@@ -0,0 +1,25 @@
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce4.rs:12:32
+   |
+LL |     let f2: &Fat<[isize; 3]> = f1;
+   |             ----------------   ^^ expected array `[isize; 3]`, found slice `[isize]`
+   |             |
+   |             expected due to this
+   |
+   = note: expected reference `&Fat<[isize; 3]>`
+              found reference `&Fat<[isize]>`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coerce4.rs:20:30
+   |
+LL |     let f2: &([isize; 3],) = f1;
+   |             --------------   ^^ expected array `[isize; 3]`, found slice `[isize]`
+   |             |
+   |             expected due to this
+   |
+   = note: expected reference `&([isize; 3],)`
+              found reference `&([isize],)`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/dst/dst-bad-coercions.rs b/tests/ui/dst/dst-bad-coercions.rs
new file mode 100644
index 00000000000..bffef378c92
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coercions.rs
@@ -0,0 +1,26 @@
+// Test implicit coercions involving DSTs and raw pointers.
+
+struct S;
+trait T {}
+impl T for S {}
+
+struct Foo<T: ?Sized> {
+    f: T
+}
+
+pub fn main() {
+    // Test that we cannot convert from *-ptr to &S and &T
+    let x: *const S = &S;
+    let y: &S = x; //~ ERROR mismatched types
+    let y: &dyn T = x; //~ ERROR mismatched types
+
+    // Test that we cannot convert from *-ptr to &S and &T (mut version)
+    let x: *mut S = &mut S;
+    let y: &S = x; //~ ERROR mismatched types
+    let y: &dyn T = x; //~ ERROR mismatched types
+
+    // Test that we cannot convert an immutable ptr to a mutable one using *-ptrs
+    let x: &mut dyn T = &S; //~ ERROR mismatched types
+    let x: *mut dyn T = &S; //~ ERROR mismatched types
+    let x: *mut S = &S; //~ ERROR mismatched types
+}
diff --git a/tests/ui/dst/dst-bad-coercions.stderr b/tests/ui/dst/dst-bad-coercions.stderr
new file mode 100644
index 00000000000..0d6f4d0209f
--- /dev/null
+++ b/tests/ui/dst/dst-bad-coercions.stderr
@@ -0,0 +1,80 @@
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:14:17
+   |
+LL |     let y: &S = x;
+   |            --   ^ expected `&S`, found `*const S`
+   |            |
+   |            expected due to this
+   |
+   = note: expected reference `&S`
+            found raw pointer `*const S`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:15:21
+   |
+LL |     let y: &dyn T = x;
+   |            ------   ^ expected `&dyn T`, found `*const S`
+   |            |
+   |            expected due to this
+   |
+   = note: expected reference `&dyn T`
+            found raw pointer `*const S`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:19:17
+   |
+LL |     let y: &S = x;
+   |            --   ^ expected `&S`, found `*mut S`
+   |            |
+   |            expected due to this
+   |
+   = note: expected reference `&S`
+            found raw pointer `*mut S`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:20:21
+   |
+LL |     let y: &dyn T = x;
+   |            ------   ^ expected `&dyn T`, found `*mut S`
+   |            |
+   |            expected due to this
+   |
+   = note: expected reference `&dyn T`
+            found raw pointer `*mut S`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:23:25
+   |
+LL |     let x: &mut dyn T = &S;
+   |            ----------   ^^ types differ in mutability
+   |            |
+   |            expected due to this
+   |
+   = note: expected mutable reference `&mut dyn T`
+                      found reference `&S`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:24:25
+   |
+LL |     let x: *mut dyn T = &S;
+   |            ----------   ^^ types differ in mutability
+   |            |
+   |            expected due to this
+   |
+   = note: expected raw pointer `*mut dyn T`
+                found reference `&S`
+
+error[E0308]: mismatched types
+  --> $DIR/dst-bad-coercions.rs:25:21
+   |
+LL |     let x: *mut S = &S;
+   |            ------   ^^ types differ in mutability
+   |            |
+   |            expected due to this
+   |
+   = note: expected raw pointer `*mut S`
+                found reference `&S`
+
+error: aborting due to 7 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/dst/dst-bad-deep-2.rs b/tests/ui/dst/dst-bad-deep-2.rs
new file mode 100644
index 00000000000..e587399135d
--- /dev/null
+++ b/tests/ui/dst/dst-bad-deep-2.rs
@@ -0,0 +1,13 @@
+// Try to initialise a DST struct where the lost information is deeply nested.
+// This is an error because it requires an unsized rvalue. This is a problem
+// because it would require stack allocation of an unsized temporary (*g in the
+// test).
+
+#![feature(unsized_tuple_coercion)]
+
+pub fn main() {
+    let f: ([isize; 3],) = ([5, 6, 7],);
+    let g: &([isize],) = &f;
+    let h: &(([isize],),) = &(*g,);
+    //~^ ERROR the size for values of type
+}
diff --git a/tests/ui/dst/dst-bad-deep-2.stderr b/tests/ui/dst/dst-bad-deep-2.stderr
new file mode 100644
index 00000000000..b2285081410
--- /dev/null
+++ b/tests/ui/dst/dst-bad-deep-2.stderr
@@ -0,0 +1,14 @@
+error[E0277]: the size for values of type `[isize]` cannot be known at compilation time
+  --> $DIR/dst-bad-deep-2.rs:11:30
+   |
+LL |     let h: &(([isize],),) = &(*g,);
+   |                              ^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `(([isize],),)`, the trait `Sized` is not implemented for `[isize]`
+   = note: required because it appears within the type `([isize],)`
+   = note: required because it appears within the type `(([isize],),)`
+   = note: tuples must have a statically known size to be initialized
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-bad-deep.rs b/tests/ui/dst/dst-bad-deep.rs
new file mode 100644
index 00000000000..a4267296082
--- /dev/null
+++ b/tests/ui/dst/dst-bad-deep.rs
@@ -0,0 +1,15 @@
+// Try to initialise a DST struct where the lost information is deeply nested.
+// This is an error because it requires an unsized rvalue. This is a problem
+// because it would require stack allocation of an unsized temporary (*g in the
+// test).
+
+struct Fat<T: ?Sized> {
+    ptr: T
+}
+
+pub fn main() {
+    let f: Fat<[isize; 3]> = Fat { ptr: [5, 6, 7] };
+    let g: &Fat<[isize]> = &f;
+    let h: &Fat<Fat<[isize]>> = &Fat { ptr: *g };
+    //~^ ERROR the size for values of type
+}
diff --git a/tests/ui/dst/dst-bad-deep.stderr b/tests/ui/dst/dst-bad-deep.stderr
new file mode 100644
index 00000000000..98db7959115
--- /dev/null
+++ b/tests/ui/dst/dst-bad-deep.stderr
@@ -0,0 +1,17 @@
+error[E0277]: the size for values of type `[isize]` cannot be known at compilation time
+  --> $DIR/dst-bad-deep.rs:13:34
+   |
+LL |     let h: &Fat<Fat<[isize]>> = &Fat { ptr: *g };
+   |                                  ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `Fat<Fat<[isize]>>`, the trait `Sized` is not implemented for `[isize]`
+note: required because it appears within the type `Fat<[isize]>`
+  --> $DIR/dst-bad-deep.rs:6:8
+   |
+LL | struct Fat<T: ?Sized> {
+   |        ^^^
+   = note: structs must have a statically known size to be initialized
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-index.rs b/tests/ui/dst/dst-index.rs
new file mode 100644
index 00000000000..2f2c5df4626
--- /dev/null
+++ b/tests/ui/dst/dst-index.rs
@@ -0,0 +1,37 @@
+// Test that overloaded index expressions with DST result types
+// can't be used as rvalues
+
+use std::ops::Index;
+use std::fmt::Debug;
+
+#[derive(Copy, Clone)]
+struct S;
+
+impl Index<usize> for S {
+    type Output = str;
+
+    fn index(&self, _: usize) -> &str {
+        "hello"
+    }
+}
+
+#[derive(Copy, Clone)]
+struct T;
+
+impl Index<usize> for T {
+    type Output = dyn Debug + 'static;
+
+    fn index<'a>(&'a self, idx: usize) -> &'a (dyn Debug + 'static) {
+        static x: usize = 42;
+        &x
+    }
+}
+
+fn main() {
+    S[0];
+    //~^ ERROR cannot move out of index of `S`
+    //~^^ ERROR E0161
+    T[0];
+    //~^ ERROR cannot move out of index of `T`
+    //~^^ ERROR E0161
+}
diff --git a/tests/ui/dst/dst-index.stderr b/tests/ui/dst/dst-index.stderr
new file mode 100644
index 00000000000..d38af3f89c2
--- /dev/null
+++ b/tests/ui/dst/dst-index.stderr
@@ -0,0 +1,28 @@
+error[E0161]: cannot move a value of type `str`
+  --> $DIR/dst-index.rs:31:5
+   |
+LL |     S[0];
+   |     ^^^^ the size of `str` cannot be statically determined
+
+error[E0161]: cannot move a value of type `dyn Debug`
+  --> $DIR/dst-index.rs:34:5
+   |
+LL |     T[0];
+   |     ^^^^ the size of `dyn Debug` cannot be statically determined
+
+error[E0507]: cannot move out of index of `S`
+  --> $DIR/dst-index.rs:31:5
+   |
+LL |     S[0];
+   |     ^^^^ move occurs because value has type `str`, which does not implement the `Copy` trait
+
+error[E0507]: cannot move out of index of `T`
+  --> $DIR/dst-index.rs:34:5
+   |
+LL |     T[0];
+   |     ^^^^ move occurs because value has type `dyn Debug`, which does not implement the `Copy` trait
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0161, E0507.
+For more information about an error, try `rustc --explain E0161`.
diff --git a/tests/ui/dst/dst-object-from-unsized-type.rs b/tests/ui/dst/dst-object-from-unsized-type.rs
new file mode 100644
index 00000000000..3cd5b1ed6f4
--- /dev/null
+++ b/tests/ui/dst/dst-object-from-unsized-type.rs
@@ -0,0 +1,27 @@
+// Test that we cannot create objects from unsized types.
+
+trait Foo { fn foo(&self) {} }
+impl Foo for str {}
+impl Foo for [u8] {}
+
+fn test1<T: ?Sized + Foo>(t: &T) {
+    let u: &dyn Foo = t;
+    //~^ ERROR the size for values of type
+}
+
+fn test2<T: ?Sized + Foo>(t: &T) {
+    let v: &dyn Foo = t as &dyn Foo;
+    //~^ ERROR the size for values of type
+}
+
+fn test3() {
+    let _: &[&dyn Foo] = &["hi"];
+    //~^ ERROR the size for values of type
+}
+
+fn test4(x: &[u8]) {
+    let _: &dyn Foo = x as &dyn Foo;
+    //~^ ERROR the size for values of type
+}
+
+fn main() { }
diff --git a/tests/ui/dst/dst-object-from-unsized-type.stderr b/tests/ui/dst/dst-object-from-unsized-type.stderr
new file mode 100644
index 00000000000..e24c96ebed6
--- /dev/null
+++ b/tests/ui/dst/dst-object-from-unsized-type.stderr
@@ -0,0 +1,51 @@
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> $DIR/dst-object-from-unsized-type.rs:8:23
+   |
+LL | fn test1<T: ?Sized + Foo>(t: &T) {
+   |          - this type parameter needs to be `std::marker::Sized`
+LL |     let u: &dyn Foo = t;
+   |                       ^ doesn't have a size known at compile-time
+   |
+   = note: required for the cast from `T` to the object type `dyn Foo`
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+LL - fn test1<T: ?Sized + Foo>(t: &T) {
+LL + fn test1<T: Foo>(t: &T) {
+   |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> $DIR/dst-object-from-unsized-type.rs:13:23
+   |
+LL | fn test2<T: ?Sized + Foo>(t: &T) {
+   |          - this type parameter needs to be `std::marker::Sized`
+LL |     let v: &dyn Foo = t as &dyn Foo;
+   |                       ^ doesn't have a size known at compile-time
+   |
+   = note: required for the cast from `T` to the object type `dyn Foo`
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+LL - fn test2<T: ?Sized + Foo>(t: &T) {
+LL + fn test2<T: Foo>(t: &T) {
+   |
+
+error[E0277]: the size for values of type `str` cannot be known at compilation time
+  --> $DIR/dst-object-from-unsized-type.rs:18:28
+   |
+LL |     let _: &[&dyn Foo] = &["hi"];
+   |                            ^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `str`
+   = note: required for the cast from `str` to the object type `dyn Foo`
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> $DIR/dst-object-from-unsized-type.rs:23:23
+   |
+LL |     let _: &dyn Foo = x as &dyn Foo;
+   |                       ^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[u8]`
+   = note: required for the cast from `[u8]` to the object type `dyn Foo`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-rvalue.rs b/tests/ui/dst/dst-rvalue.rs
new file mode 100644
index 00000000000..fbb32cac128
--- /dev/null
+++ b/tests/ui/dst/dst-rvalue.rs
@@ -0,0 +1,10 @@
+// Check that dynamically sized rvalues are forbidden
+
+pub fn main() {
+    let _x: Box<str> = Box::new(*"hello world");
+    //~^ ERROR E0277
+
+    let array: &[isize] = &[1, 2, 3];
+    let _x: Box<[isize]> = Box::new(*array);
+    //~^ ERROR E0277
+}
diff --git a/tests/ui/dst/dst-rvalue.stderr b/tests/ui/dst/dst-rvalue.stderr
new file mode 100644
index 00000000000..8d0a82b707d
--- /dev/null
+++ b/tests/ui/dst/dst-rvalue.stderr
@@ -0,0 +1,27 @@
+error[E0277]: the size for values of type `str` cannot be known at compilation time
+  --> $DIR/dst-rvalue.rs:4:33
+   |
+LL |     let _x: Box<str> = Box::new(*"hello world");
+   |                        -------- ^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |                        |
+   |                        required by a bound introduced by this call
+   |
+   = help: the trait `Sized` is not implemented for `str`
+note: required by a bound in `Box::<T>::new`
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+
+error[E0277]: the size for values of type `[isize]` cannot be known at compilation time
+  --> $DIR/dst-rvalue.rs:8:37
+   |
+LL |     let _x: Box<[isize]> = Box::new(*array);
+   |                            -------- ^^^^^^ doesn't have a size known at compile-time
+   |                            |
+   |                            required by a bound introduced by this call
+   |
+   = help: the trait `Sized` is not implemented for `[isize]`
+note: required by a bound in `Box::<T>::new`
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dst/dst-sized-trait-param.rs b/tests/ui/dst/dst-sized-trait-param.rs
new file mode 100644
index 00000000000..cfd59197bec
--- /dev/null
+++ b/tests/ui/dst/dst-sized-trait-param.rs
@@ -0,0 +1,13 @@
+// Check that when you implement a trait that has a sized type
+// parameter, the corresponding value must be sized. Also that the
+// self type must be sized if appropriate.
+
+trait Foo<T> : Sized { fn take(self, x: &T) { } } // Note: T is sized
+
+impl Foo<[isize]> for usize { }
+//~^ ERROR the size for values of type
+
+impl Foo<isize> for [usize] { }
+//~^ ERROR the size for values of type
+
+pub fn main() { }
diff --git a/tests/ui/dst/dst-sized-trait-param.stderr b/tests/ui/dst/dst-sized-trait-param.stderr
new file mode 100644
index 00000000000..8ec94f5a3c0
--- /dev/null
+++ b/tests/ui/dst/dst-sized-trait-param.stderr
@@ -0,0 +1,33 @@
+error[E0277]: the size for values of type `[isize]` cannot be known at compilation time
+  --> $DIR/dst-sized-trait-param.rs:7:6
+   |
+LL | impl Foo<[isize]> for usize { }
+   |      ^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[isize]`
+note: required by a bound in `Foo`
+  --> $DIR/dst-sized-trait-param.rs:5:11
+   |
+LL | trait Foo<T> : Sized { fn take(self, x: &T) { } } // Note: T is sized
+   |           ^ required by this bound in `Foo`
+help: consider relaxing the implicit `Sized` restriction
+   |
+LL | trait Foo<T: ?Sized> : Sized { fn take(self, x: &T) { } } // Note: T is sized
+   |            ++++++++
+
+error[E0277]: the size for values of type `[usize]` cannot be known at compilation time
+  --> $DIR/dst-sized-trait-param.rs:10:6
+   |
+LL | impl Foo<isize> for [usize] { }
+   |      ^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[usize]`
+note: required by a bound in `Foo`
+  --> $DIR/dst-sized-trait-param.rs:5:16
+   |
+LL | trait Foo<T> : Sized { fn take(self, x: &T) { } } // Note: T is sized
+   |                ^^^^^ required by this bound in `Foo`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.