Add support for generic types to easy_wrapper (#54)

Author: notgull

strategy/src/lib.rs

@@ -130,19 +130,75 @@ pub use pin_project_lite::pin_project;
 macro_rules! easy_wrapper {
     (
         $(#[$meta:meta])*
-        $vis:vis struct $name:ident ($inner:ty => $output:ty);
+        $vis:vis struct $name:ident
+
+        $(<
+            $( $lifetime:lifetime $(: $lifetime_bound:lifetime)? ),* $(,)?
+            $( $generics:ident
+                $(: $generics_bound:path)?
+                $(: ?$generics_unsized_bound:path)?
+                $(: $generics_lifetime_bound:lifetime)?
+                $(= $generics_default:ty)?
+            ),* $(,)?
+        >)?
+
+        ($inner:ty => $output:ty)
+
+        $(where
+            $( $where_clause_ty:ty
+                $(: $where_clause_bound:path)?
+                $(: ?$where_clause_unsized_bound:path)?
+                $(: $where_clause_lifetime_bound:lifetime)?
+            ),* $(,)?
+        )?
+
+        ;
+
         $(#[$wait_meta:meta])*
         $wait_vis: vis wait();
     ) => {
         $crate::pin_project! {
             $(#[$meta])*
-            $vis struct $name {
+            $vis struct $name $(<
+                $( $lifetime $(: $lifetime_bound)? ),*
+                $( $generics
+                    $(: $generics_bound)?
+                    $(: ?$generics_unsized_bound)?
+                    $(: $generics_lifetime_bound)?
+                    $(= $generics_default)?
+                ),*
+            >)? $(
+                where
+                $( $where_clause_ty
+                    $(: $where_clause_bound)?
+                    $(: ?$where_clause_unsized_bound)?
+                    $(: $where_clause_lifetime_bound)?
+                ),*
+            )? {
                 #[pin]
                 _inner: $crate::FutureWrapper<$inner>
             }
         }
 
-        impl $name {
+        impl $(<
+            $( $lifetime $(: $lifetime_bound)? ,)*
+            $( $generics
+                $(: $generics_bound)?
+                $(: ?$generics_unsized_bound)?
+                $(: $generics_lifetime_bound)?
+                $(= $generics_default)?
+            ),*
+        >)? $name $(<
+            $( $lifetime ,)*
+            $( $generics ),*
+        >)? $(
+            where
+            $( $where_clause_ty
+                $(: $where_clause_bound)?
+                $(: ?$where_clause_unsized_bound)?
+                $(: $where_clause_lifetime_bound)?
+            ),*
+        )? {
             #[inline]
             fn _new(inner: $inner) -> Self {
                 Self {
@@ -158,7 +214,27 @@ macro_rules! easy_wrapper {
             }
         }
 
-        impl ::core::future::Future for $name {
+        impl $(<
+            $( $lifetime $(: $lifetime_bound)? ,)*
+            $( $generics
+                $(: $generics_bound)?
+                $(: ?$generics_unsized_bound)?
+                $(: $generics_lifetime_bound)?
+                $(= $generics_default)?
+            ),*
+        >)? ::core::future::Future for $name $(
+            <
+                $( $lifetime ,)*
+                $( $generics ),*
+            >
+        )? $(
+            where
+            $( $where_clause_ty
+                $(: $where_clause_bound)?
+                $(: ?$where_clause_unsized_bound)?
+                $(: $where_clause_lifetime_bound)?
+            ),*
+        )? {
             type Output = $output;
 
             #[inline]

strategy/tests/easy_wrapper.rs

@@ -0,0 +1,102 @@
+//! Testing of the `easy_wrapper!` macro.
+
+use std::{marker::PhantomData, pin::Pin, task::Poll};
+
+use event_listener_strategy::{easy_wrapper, EventListenerFuture, Strategy};
+
+#[test]
+fn easy_wrapper_generics() {
+    // Easy case.
+    struct MyStrategy;
+
+    impl EventListenerFuture for MyStrategy {
+        type Output = ();
+
+        fn poll_with_strategy<'a, S: Strategy<'a>>(
+            self: Pin<&'a mut Self>,
+            _strategy: &mut S,
+            _context: &mut S::Context,
+        ) -> Poll<Self::Output> {
+            Poll::Ready(())
+        }
+    }
+
+    easy_wrapper! {
+        struct MyEasyWrapper(MyStrategy => ());
+        wait();
+    }
+
+    MyEasyWrapper::_new(MyStrategy).wait();
+
+    // Medium case with generics.
+    struct MyStrategy2<T> {
+        _marker: PhantomData<T>,
+    }
+
+    impl<T> EventListenerFuture for MyStrategy2<T> {
+        type Output = T;
+
+        fn poll_with_strategy<'a, S: Strategy<'a>>(
+            self: Pin<&'a mut Self>,
+            _strategy: &mut S,
+            _context: &mut S::Context,
+        ) -> Poll<Self::Output> {
+            unreachable!()
+        }
+    }
+
+    easy_wrapper! {
+        struct MyEasyWrapper2<T>(MyStrategy2<T> => T);
+        wait();
+    }
+
+    // Medium mode with lifetime.
+    struct MyStrategylt<'a> {
+        _marker: PhantomData<&'a ()>,
+    }
+
+    impl<'a> EventListenerFuture for MyStrategylt<'a> {
+        type Output = &'a ();
+
+        fn poll_with_strategy<'b, S: Strategy<'b>>(
+            self: Pin<&'b mut Self>,
+            _strategy: &mut S,
+            _context: &mut S::Context,
+        ) -> Poll<Self::Output> {
+            unreachable!()
+        }
+    }
+
+    easy_wrapper! {
+        struct MyEasyWrapperlt<'a>(MyStrategylt<'a> => &'a ());
+        wait();
+    }
+
+    // Hard mode with generic bounds.
+    struct MyStrategy3<'a, T: ?Sized>
+    where
+        T: 'a,
+    {
+        _marker: PhantomData<&'a T>,
+    }
+
+    impl<'a, T: ?Sized> EventListenerFuture for MyStrategy3<'a, T>
+    where
+        T: 'a,
+    {
+        type Output = &'a T;
+
+        fn poll_with_strategy<'b, S: Strategy<'b>>(
+            self: Pin<&'b mut Self>,
+            _strategy: &mut S,
+            _context: &mut S::Context,
+        ) -> Poll<Self::Output> {
+            unreachable!()
+        }
+    }
+
+    easy_wrapper! {
+        struct MyEasyWrapper3<'a, T: ?Sized>(MyStrategy3<'a, T> => &'a T) where T: 'a;
+        wait();
+    }
+}