Fix breakage on latest nightly.

.github/bors.toml

@@ -1,5 +1,5 @@
 status = [
-    "test (nightly-2019-08-21)",
+    "test (nightly-2020-02-14)",
     "test (nightly)",
     "style (clippy)",
     "style (rustfmt)",

.github/workflows/ci.yml

@@ -23,8 +23,7 @@ jobs:
           # This is the minimum supported Rust version of this crate.
           # When updating this, the reminder to update the minimum supported
           # Rust version in README.md.
-          - nightly-2019-08-21
-          - nightly-2019-12-09
+          - nightly-2020-02-14
           - nightly
     steps:
       - uses: actions/checkout@master

README.md

@@ -27,7 +27,7 @@ futures-async-stream = "0.1"
 futures = "0.3"
 ```
 
-The current futures-async-stream requires Rust nightly 2019-08-21 or later.
+The current futures-async-stream requires Rust nightly 2020-02-14 or later.
 
 ## \#\[for_await\]
 

src/lib.rs

@@ -294,7 +294,7 @@ pub mod future {
         fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
             let this = self.project();
             let _guard = unsafe { set_task_context(cx) };
-            match this.0.resume() {
+            match this.0.resume(()) {
                 GeneratorState::Yielded(()) => Poll::Pending,
                 GeneratorState::Complete(x) => Poll::Ready(x),
             }
@@ -376,7 +376,7 @@ pub mod stream {
         fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
             let this = self.project();
             let _guard = unsafe { set_task_context(cx) };
-            match this.gen.resume() {
+            match this.gen.resume(()) {
                 GeneratorState::Yielded(x) => x.map(Some),
                 GeneratorState::Complete(()) => Poll::Ready(None),
             }
@@ -492,7 +492,7 @@ pub mod try_stream {
 
             let this = self.project();
             let _guard = unsafe { set_task_context(cx) };
-            let res = match this.gen.resume() {
+            let res = match this.gen.resume(()) {
                 GeneratorState::Yielded(x) => x.map(|x| Some(Ok(x))),
                 GeneratorState::Complete(Err(e)) => Poll::Ready(Some(Err(e))),
                 GeneratorState::Complete(Ok(())) => Poll::Ready(None),

tests/ui/bad-item-type.stderr

@@ -21,6 +21,7 @@ note: the type is part of the generator because of this `yield`
   |
 5 | #[async_stream(item = Option<i32>)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0698]: type inside generator must be known in this context
   --> $DIR/bad-item-type.rs:12:9
@@ -33,6 +34,7 @@ note: the type is part of the generator because of this `yield`
    |
 5  | #[async_stream(item = Option<i32>)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0698]: type inside generator must be known in this context
   --> $DIR/bad-item-type.rs:13:11
@@ -45,6 +47,7 @@ note: the type is part of the generator because of this `yield`
    |
 5  | #[async_stream(item = Option<i32>)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0308]: mismatched types
   --> $DIR/bad-item-type.rs:21:11
@@ -76,6 +79,7 @@ note: the type is part of the generator because of this `yield`
    |
 16 | #[async_stream(item = (i32, i32))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0698]: type inside generator must be known in this context
   --> $DIR/bad-item-type.rs:16:1
@@ -88,6 +92,7 @@ note: the type is part of the generator because of this `yield`
    |
 16 | #[async_stream(item = (i32, i32))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0698]: type inside generator must be known in this context
   --> $DIR/bad-item-type.rs:21:12
@@ -100,6 +105,7 @@ note: the type is part of the generator because of this `yield`
    |
 16 | #[async_stream(item = (i32, i32))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0698]: type inside generator must be known in this context
   --> $DIR/bad-item-type.rs:21:15
@@ -112,6 +118,7 @@ note: the type is part of the generator because of this `yield`
    |
 16 | #[async_stream(item = (i32, i32))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0698]: type inside generator must be known in this context
   --> $DIR/bad-item-type.rs:21:11
@@ -124,3 +131,4 @@ note: the type is part of the generator because of this `yield`
    |
 16 | #[async_stream(item = (i32, i32))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui/missing-item.stderr

@@ -3,3 +3,5 @@ error: unexpected end of input, expected `item`
   |
 5 | #[async_stream] //~ ERROR unexpected end of input, expected `item`
   | ^^^^^^^^^^^^^^^
+  |
+  = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui/move-captured-variable.stderr

@@ -11,7 +11,6 @@ error[E0507]: cannot move out of `a`, a captured variable in an `FnMut` closure
    | |                   move occurs because `a` has type `std::string::String`, which does not implement the `Copy` trait
    | |                   move occurs due to use in generator
 12 | |         };
-   | |          ^
-   | |          |
-   | |__________move out of `a` occurs here
-   |            in this macro invocation
+   | |__________^ move out of `a` occurs here
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui/unresolved-type.stderr

@@ -27,3 +27,4 @@ note: the type is part of the generator because of this `yield`
   |
 5 | #[async_stream(item = Left)] //~ ERROR cannot find type `Left` in this scope
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)