Implement ? in catch expressions and add tests

src/test/compile-fail/catch-bad-lifetime.rs

@@ -0,0 +1,35 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(catch_expr)]
+
+pub fn main() {
+    let _: Result<(), &str> = do catch {
+        let my_string = String::from("");
+        let my_str: &str = &my_string;
+        Err(my_str)?;
+        Err("")?;
+        Ok(())
+    }; //~ ERROR `my_string` does not live long enough
+
+    let mut i = 5;
+    let k = &mut i;
+    let mut j: Result<(), &mut i32> = do catch {
+        Err(k)?;
+        i = 10; //~ ERROR cannot assign to `i` because it is borrowed
+        Ok(())
+    };
+    ::std::mem::drop(k); //~ ERROR use of moved value: `k`
+    i = 40; //~ ERROR cannot assign to `i` because it is borrowed
+
+    let i_ptr = if let Err(i_ptr) = j { i_ptr } else { panic!("") };
+    *i_ptr = 50;
+}
+

src/test/compile-fail/catch-bad-type.rs

@@ -0,0 +1,21 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(catch_expr)]
+
+pub fn main() {
+    let res: Result<i32, i32> = do catch {
+        Err("")?; //~ ERROR the trait bound `i32: std::convert::From<&str>` is not satisfied
+        Ok(5)
+    };
+    let res: Result<i32, i32> = do catch {
+        Ok("") //~ mismatched types
+    };
+}

src/test/compile-fail/catch-opt-init.rs

@@ -0,0 +1,22 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(catch_expr)]
+
+pub fn main() {
+    let cfg_res;
+    let _: Result<(), ()> = do catch {
+        Err(())?;
+        cfg_res = 5;
+        Ok(())
+    };
+    assert_eq!(cfg_res, 5); //~ ERROR use of possibly uninitialized variable
+}
+

src/test/run-pass/catch-expr.rs

@@ -29,4 +29,38 @@ pub fn main() {
     match catch {
         _ => {}
     };
+
+    let catch_err = do catch {
+        Err(22)?;
+        Ok(1)
+    };
+    assert_eq!(catch_err, Err(22));
+
+    let catch_okay: Result<i32, i32> = do catch {
+        if false { Err(25)?; }
+        Ok::<(), i32>(())?;
+        Ok(28)
+    };
+    assert_eq!(catch_okay, Ok(28));
+
+    let catch_from_loop: Result<i32, i32> = do catch {
+        for i in 0..10 {
+            if i < 5 { Ok::<i32, i32>(i)?; } else { Err(i)?; }
+        }
+        Ok(22)
+    };
+    assert_eq!(catch_from_loop, Err(5));
+
+    let cfg_init;
+    let _res: Result<(), ()> = do catch {
+        cfg_init = 5;
+        Ok(())
+    };
+    assert_eq!(cfg_init, 5);
+
+    let my_string = "test".to_string();
+    let res: Result<&str, ()> = do catch {
+        Ok(&my_string)
+    };
+    assert_eq!(res, Ok("test"));
 }