move blosure tests to closures file; test Box<dyn> a bit more

Author: RalfJung

tests/run-pass/closures.rs

@@ -40,10 +40,21 @@ fn fn_once_closure_with_multiple_args() -> i64 {
     }
 }
 
-fn boxed(f: Box<dyn FnOnce() -> i32>) -> i32 {
+fn boxed_fn_once(f: Box<dyn FnOnce() -> i32>) -> i32 {
     f()
 }
 
+fn box_dyn() {
+    let x: Box<dyn Fn(i32) -> i32> = Box::new(|x| x * 2);
+    assert_eq!(x(21), 42);
+    let mut i = 5;
+    {
+        let mut x: Box<dyn FnMut()> = Box::new(|| i *= 2);
+        x(); x();
+    }
+    assert_eq!(i, 20);
+}
+
 fn fn_item_as_closure_trait_object() {
     fn foo() {}
     let f: &dyn Fn() = &foo;
@@ -96,8 +107,9 @@ fn main() {
     assert_eq!(crazy_closure(), (84, 10, 10));
     assert_eq!(closure_arg_adjustment_problem(), 3);
     assert_eq!(fn_once_closure_with_multiple_args(), 6);
-    assert_eq!(boxed(Box::new({let x = 13; move || x})), 13);
+    assert_eq!(boxed_fn_once(Box::new({let x = 13; move || x})), 13);
 
+    box_dyn();
     fn_item_as_closure_trait_object();
     fn_item_with_args_as_closure_trait_object();
     fn_item_with_multiple_args_as_closure_trait_object();

tests/run-pass/dyn-traits.rs

@@ -1,6 +1,6 @@
 #![feature(unsized_locals)]
 
-fn ref_dyn() {
+fn ref_box_dyn() {
     struct Struct(i32);
 
     trait Trait {
@@ -17,22 +17,19 @@ fn ref_dyn() {
 
     let y: &dyn Trait = &Struct(42);
     y.method();
+
     let x: Foo<Struct> = Foo(Struct(42));
     let y: &Foo<dyn Trait> = &x;
     y.0.method();
-}
 
-fn box_dyn() {
-    let x: Box<dyn Fn(i32) -> i32> = Box::new(|x| x * 2);
-    assert_eq!(x(21), 42);
-    let mut i = 5;
-    {
-        let mut x: Box<dyn FnMut()> = Box::new(|| i *= 2);
-        x(); x();
-    }
-    assert_eq!(i, 20);
+    let y: Box<dyn Trait> = Box::new(Struct(42));
+    y.method();
+
+    let y = &y;
+    y.method();
 }
 
+
 fn box_box_trait() {
     struct DroppableStruct;
 
@@ -130,8 +127,7 @@ fn unsized_dyn_autoderef() {
 }
 
 fn main() {
-    ref_dyn();
-    box_dyn();
+    ref_box_dyn();
     box_box_trait();
 
     // "exotic" receivers