Add and fix tests for coercion between (FnDef | Closure) and (FnDef | Closure)

Author: ldm0

src/test/ui/issues/issue-24036.rs

@@ -10,7 +10,7 @@ fn closure_from_match() {
         2 => |c| c - 1,
         _ => |c| c - 1
     };
-    //~^^^ ERROR `match` arms have incompatible types
+    //~^^^^ ERROR 9:15: 9:16: type annotations needed [E0282]
 }
 
 fn main() { }

src/test/ui/issues/issue-24036.stderr

@@ -11,24 +11,13 @@ LL |     x = |c| c + 1;
    = note: no two closures, even if identical, have the same type
    = help: consider boxing your closure and/or using it as a trait object
 
-error[E0308]: `match` arms have incompatible types
-  --> $DIR/issue-24036.rs:10:14
+error[E0282]: type annotations needed
+  --> $DIR/issue-24036.rs:9:15
    |
-LL |       let x = match 1usize {
-   |  _____________-
-LL | |         1 => |c| c + 1,
-   | |              --------- this is found to be of type `[closure@$DIR/issue-24036.rs:9:14: 9:23]`
-LL | |         2 => |c| c - 1,
-   | |              ^^^^^^^^^ expected closure, found a different closure
-LL | |         _ => |c| c - 1
-LL | |     };
-   | |_____- `match` arms have incompatible types
-   |
-   = note: expected type `[closure@$DIR/issue-24036.rs:9:14: 9:23]`
-           found closure `[closure@$DIR/issue-24036.rs:10:14: 10:23]`
-   = note: no two closures, even if identical, have the same type
-   = help: consider boxing your closure and/or using it as a trait object
+LL |         1 => |c| c + 1,
+   |               ^ consider giving this closure parameter a type
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0282, E0308.
+For more information about an error, try `rustc --explain E0282`.

src/test/ui/issues/issue-46742-1.rs

@@ -0,0 +1,51 @@
+// check-pass
+fn main() {
+    let _: i32 = (match "" {
+        "+" => ::std::ops::Add::add,
+        "-" => ::std::ops::Sub::sub,
+        "<" => |a,b| (a < b) as i32,
+        _ => unimplemented!(),
+    })(5, 5);
+    let _: i32 = (match "" {
+        "-" => ::std::ops::Sub::sub,
+        "<" => |a,b| (a < b) as i32,
+        "+" => ::std::ops::Add::add,
+        _ => unimplemented!(),
+    })(5, 5);
+    let _: i32 = (match "" {
+        "<" => |a,b| (a < b) as i32,
+        "+" => ::std::ops::Add::add,
+        "-" => ::std::ops::Sub::sub,
+        _ => unimplemented!(),
+    })(5, 5);
+
+    let _: i32 = (match "" {
+        "+" => ::std::ops::Add::add,
+        "<" => |a,b| (a < b) as i32,
+        _ => unimplemented!(),
+    })(5, 5);
+    let _: i32 = (match "" {
+        "<" => |a,b| (a < b) as i32,
+        "+" => ::std::ops::Add::add,
+        _ => unimplemented!(),
+    })(5, 5);
+
+    let _: i32 = (match "" {
+        "+" => |c,d| (c > d) as i32,
+        "<" => |a,b| (a < b) as i32,
+        "-" => ::std::ops::Sub::sub,
+        _ => unimplemented!(),
+    })(5, 5);
+    let _: i32 = (match "" {
+        "<" => |a,b| (a < b) as i32,
+        "-" => ::std::ops::Sub::sub,
+        "+" => |c,d| (c > d) as i32,
+        _ => unimplemented!(),
+    })(5, 5);
+    let _: i32 = (match "" {
+        "-" => ::std::ops::Sub::sub,
+        "+" => |c,d| (c > d) as i32,
+        "<" => |a,b| (a < b) as i32,
+        _ => unimplemented!(),
+    })(5, 5);
+}

src/test/ui/issues/issue-46742-2.rs

@@ -0,0 +1,11 @@
+unsafe fn add(a: i32, b: i32) -> i32 {
+    a + b
+}
+fn main() {
+    let foo = match "+" {
+        "+" => add,
+        "-" => |a,b| (a - b) as i32,
+        _ => unimplemented!(),
+    };
+    let result: i32 = foo(5, 5); //~ ERROR call to unsafe function
+}

src/test/ui/issues/issue-46742-2.stderr

@@ -0,0 +1,11 @@
+error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+  --> $DIR/issue-46742-2.rs:10:23
+   |
+LL |     let result: i32 = foo(5, 5);
+   |                       ^^^^^^^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.