Add `: Box<_>` or `::Box<_>` type annotations to various places.

This is the kind of change that one is expected to need to make to
accommodate overloaded-`box`.

----

Note that this is not *all* of the changes necessary to accommodate
Issue 22181.  It is merely the subset of those cases where there was
already a let-binding in place that made it easy to add the necesasry
type ascription.

(For unnamed intermediate `Box` values, one must go down a different
route; `Box::new` is the option that maximizes portability, but has
potential inefficiency depending on whether the call is inlined.)

----

There is one place worth note, `run-pass/coerce-match.rs`, where I
used an ugly form of `Box<_>` type ascription where I would have
preferred to use `Box::new` to accommodate overloaded-`box`.  I
deliberately did not use `Box::new` here, because that is already done
in coerce-match-calls.rs.

----

Precursor for overloaded-`box` and placement-`in`; see Issue 22181.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/test/debuginfo/method-on-tuple-struct.rs b/src/test/debuginfo/method-on-tuple-struct.rs
index cee04e92c2d..e8bc40f1810 100644
--- a/src/test/debuginfo/method-on-tuple-struct.rs
+++ b/src/test/debuginfo/method-on-tuple-struct.rs
@@ -141,7 +141,7 @@ fn main() {
     let _ = stack.self_by_ref(-1, -2);
     let _ = stack.self_by_val(-3, -4);
 
-    let owned = box TupleStruct(200, -200.5);
+    let owned: Box<_> = box TupleStruct(200, -200.5);
     let _ = owned.self_by_ref(-5, -6);
     let _ = owned.self_by_val(-7, -8);
     let _ = owned.self_owned(-9, -10);