Reword the short diagnostic for E0509

Saying that a type *implements* a trait is much more idiomatic than saying it *defines* the trait.

Author: Robin Kruppe

src/librustc_borrowck/borrowck/gather_loans/move_error.rs

@@ -152,7 +152,7 @@ fn report_cannot_move_out_of<'a, 'tcx>(bccx: &BorrowckCtxt<'a, 'tcx>,
                 ty::TyEnum(def, _) if def.has_dtor() => {
                     let mut err = struct_span_err!(bccx, move_from.span, E0509,
                                                    "cannot move out of type `{}`, \
-                                                   which defines the `Drop` trait",
+                                                   which implements the `Drop` trait",
                                                    b.ty);
                     err.span_label(move_from.span, &format!("cannot move out of here"));
                     err

src/test/compile-fail/borrowck/borrowck-move-error-with-note.rs

@@ -37,7 +37,7 @@ impl Drop for S {
 
 fn move_in_match() {
     match (S {f: "foo".to_string(), g: "bar".to_string()}) {
-        S {         //~ ERROR cannot move out of type `S`, which defines the `Drop` trait
+        S {         //~ ERROR cannot move out of type `S`, which implements the `Drop` trait
         //~| cannot move out of here
             f: _s,  //~ NOTE to prevent move
             g: _t   //~ NOTE and here

src/test/compile-fail/borrowck/borrowck-move-out-of-struct-with-dtor.rs

@@ -16,17 +16,17 @@ impl Drop for S {
 fn move_in_match() {
     match (S {f:"foo".to_string()}) {
         S {f:_s} => {}
-        //~^ ERROR cannot move out of type `S`, which defines the `Drop` trait
+        //~^ ERROR cannot move out of type `S`, which implements the `Drop` trait
     }
 }
 
 fn move_in_let() {
     let S {f:_s} = S {f:"foo".to_string()};
-    //~^ ERROR cannot move out of type `S`, which defines the `Drop` trait
+    //~^ ERROR cannot move out of type `S`, which implements the `Drop` trait
 }
 
 fn move_in_fn_arg(S {f:_s}: S) {
-    //~^ ERROR cannot move out of type `S`, which defines the `Drop` trait
+    //~^ ERROR cannot move out of type `S`, which implements the `Drop` trait
 }
 
 fn main() {}

src/test/compile-fail/borrowck/borrowck-move-out-of-tuple-struct-with-dtor.rs

@@ -16,17 +16,17 @@ impl Drop for S {
 fn move_in_match() {
     match S("foo".to_string()) {
         S(_s) => {}
-        //~^ ERROR cannot move out of type `S`, which defines the `Drop` trait
+        //~^ ERROR cannot move out of type `S`, which implements the `Drop` trait
     }
 }
 
 fn move_in_let() {
     let S(_s) = S("foo".to_string());
-    //~^ ERROR cannot move out of type `S`, which defines the `Drop` trait
+    //~^ ERROR cannot move out of type `S`, which implements the `Drop` trait
 }
 
 fn move_in_fn_arg(S(_s): S) {
-    //~^ ERROR cannot move out of type `S`, which defines the `Drop` trait
+    //~^ ERROR cannot move out of type `S`, which implements the `Drop` trait
 }
 
 fn main() {}

src/test/compile-fail/borrowck/borrowck-struct-update-with-dtor.rs

@@ -19,11 +19,13 @@ struct T { a: isize, mv: Box<isize> }
 impl Drop for T { fn drop(&mut self) { } }
 
 fn f(s0:S) {
-    let _s2 = S{a: 2, ..s0}; //~error: cannot move out of type `S`, which defines the `Drop` trait
+    let _s2 = S{a: 2, ..s0};
+    //~^ error: cannot move out of type `S`, which implements the `Drop` trait
 }
 
 fn g(s0:T) {
-    let _s2 = T{a: 2, ..s0}; //~error: cannot move out of type `T`, which defines the `Drop` trait
+    let _s2 = T{a: 2, ..s0};
+    //~^ error: cannot move out of type `T`, which implements the `Drop` trait
 }
 
 fn main() { }

src/test/compile-fail/disallowed-deconstructing-destructing-struct-match.rs

@@ -23,6 +23,6 @@ fn main() {
 
     match x {
         X { x: y } => println!("contents: {}", y)
-        //~^ ERROR cannot move out of type `X`, which defines the `Drop` trait
+        //~^ ERROR cannot move out of type `X`, which implements the `Drop` trait
     }
 }