Only consider yields coming after the expressions when computing generator interiors

src/test/run-pass/generator/borrow-in-tail-expr.rs

@@ -0,0 +1,19 @@
+// 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(generators)]
+
+fn main() {
+    let _a = || {
+        yield;
+        let a = String::new();
+        a.len()
+    };
+}

src/test/run-pass/generator/borrow-in-yield-expr.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(generators, generator_trait, conservative_impl_trait)]
+
+use std::ops::Generator;
+
+fn bar(baz: String) -> impl Generator<Yield=(), Return=()> {
+    move || {
+        yield drop(&baz);
+    }
+}
+
+fn main() {}

src/test/run-pass/generator/yield-in-args-rev.rs

@@ -12,12 +12,10 @@
 
 fn foo(_a: (), _b: &bool) {}
 
-// Some examples that probably *could* be accepted, but which we reject for now.
-
 fn bar() {
     || {
         let b = true;
-        foo(yield, &b); //~ ERROR
+        foo(yield, &b);
     };
 }
 

src/test/ui/generator/yield-in-args-rev.stderr

@@ -1,10 +0,0 @@
-error[E0626]: borrow may still be in use when generator yields
-  --> $DIR/yield-in-args-rev.rs:20:21
-   |
-20 |         foo(yield, &b); //~ ERROR
-   |             -----   ^
-   |             |
-   |             possible yield occurs here
-
-error: aborting due to previous error
-