Add tests

src/test/ui/type-inference/or_else-multiple-type-params.rs

@@ -0,0 +1,10 @@
+use std::process::{Command, Stdio};
+
+fn main() {
+    let process = Command::new("wc")
+        .stdout(Stdio::piped())
+        .spawn()
+        .or_else(|err| { //~ ERROR type annotations needed
+            panic!("oh no: {:?}", err);
+        }).unwrap();
+}

src/test/ui/type-inference/or_else-multiple-type-params.stderr

@@ -0,0 +1,12 @@
+error[E0282]: type annotations needed
+  --> $DIR/or_else-multiple-type-params.rs:7:10
+   |
+LL |         .or_else(|err| {
+   |          ^^^^^^^
+   |          |
+   |          cannot infer type for `F`
+   |          help: consider specifying the type arguments in the method call: `or_else::<F, O>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.

src/test/ui/type-inference/sort_by_key.rs

@@ -0,0 +1,5 @@
+fn main() {
+    let mut lst: [([i32; 10], bool); 10] = [([0; 10], false); 10];
+    lst.sort_by_key(|&(v, _)| v.iter().sum()); //~ ERROR type annotations needed
+    println!("{:?}", lst);
+}

src/test/ui/type-inference/sort_by_key.stderr

@@ -0,0 +1,11 @@
+error[E0282]: type annotations needed
+  --> $DIR/sort_by_key.rs:3:9
+   |
+LL |     lst.sort_by_key(|&(v, _)| v.iter().sum());
+   |         ^^^^^^^^^^^                    --- help: consider specifying the type argument in the method call: `sum::<S>`
+   |         |
+   |         cannot infer type for `K`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.