Fix TCFType macros for generic types (#652)

* Improve TCFType macros

This adds the following new features:

* `declare_TCFType!`: Generics are accepted.
* `impl_TCFType!`: Non-defaulted generics are accepted, and impls are
  fixed to be for all generics.

In addition, some warnings are silenced and the macros no longer depend
on any traits being in scope in the caller.

* Support generics in impl_CFComparison

* Add generic test for macros

Author: tmandry

core-foundation/src/characterset.rs

@@ -11,8 +11,6 @@
 
 pub use core_foundation_sys::characterset::*;
 
-use crate::base::TCFType;
-
 declare_TCFType! {
     /// An immutable set of Unicode characters.
     CFCharacterSet, CFCharacterSetRef

core-foundation/src/lib.rs

@@ -52,16 +52,25 @@ macro_rules! declare_TCFType {
     (
         $(#[$doc:meta])*
         $ty:ident, $raw:ident
+    ) => {
+        declare_TCFType!($(#[$doc])* $ty<>, $raw);
+    };
+
+    (
+        $(#[$doc:meta])*
+        $ty:ident<$($p:ident $(: $bound:path)*),*>, $raw:ident
     ) => {
         $(#[$doc])*
-        pub struct $ty($raw);
+        pub struct $ty<$($p $(: $bound)*),*>($raw, $(::std::marker::PhantomData<$p>),*);
 
-        impl Drop for $ty {
+        #[allow(unused_imports)]
+        impl<$($p $(: $bound)*),*> Drop for $ty<$($p),*> {
             fn drop(&mut self) {
+                use $crate::base::TCFType;
                 unsafe { $crate::base::CFRelease(self.as_CFTypeRef()) }
             }
         }
-    }
+    };
 }
 
 /// Provide an implementation of the [`TCFType`] trait for the Rust
@@ -82,6 +91,7 @@ macro_rules! impl_TCFType {
         impl<$($p $(: $bound)*),*> $crate::base::TCFType for $ty<$($p),*> {
             type Ref = $ty_ref;
 
+            #[allow(non_snake_case)]
             #[inline]
             fn as_concrete_TypeRef(&self) -> $ty_ref {
                 self.0
@@ -94,6 +104,7 @@ macro_rules! impl_TCFType {
                 $crate::base::TCFType::wrap_under_create_rule(reference)
             }
 
+            #[allow(non_snake_case)]
             #[inline]
             fn as_CFTypeRef(&self) -> $crate::base::CFTypeRef {
                 self.as_concrete_TypeRef() as $crate::base::CFTypeRef
@@ -115,39 +126,46 @@ macro_rules! impl_TCFType {
             }
         }
 
-        impl Clone for $ty {
+        #[allow(unused_imports)]
+        impl<$($p $(: $bound)*),*> Clone for $ty<$($p),*> {
             #[inline]
-            fn clone(&self) -> $ty {
+            fn clone(&self) -> Self {
+                use $crate::base::TCFType;
                 unsafe {
                     $ty::wrap_under_get_rule(self.0)
                 }
             }
         }
 
-        impl PartialEq for $ty {
+        #[allow(unused_imports)]
+        impl<$($p $(: $bound)*),*> PartialEq for $ty<$($p),*> {
             #[inline]
-            fn eq(&self, other: &$ty) -> bool {
+            fn eq(&self, other: &Self) -> bool {
+                use $crate::base::TCFType;
                 self.as_CFType().eq(&other.as_CFType())
             }
         }
 
-        impl Eq for $ty { }
+        impl<$($p $(: $bound)*),*> Eq for $ty<$($p),*> { }
 
-        unsafe impl<'a> $crate::base::ToVoid<$ty> for &'a $ty {
+        #[allow(unused_imports)]
+        unsafe impl<'a, $($p $(: $bound)*),*> $crate::base::ToVoid<$ty<$($p),*>> for &'a $ty<$($p),*> {
             fn to_void(&self) -> *const ::core::ffi::c_void {
-                use $crate::base::TCFTypeRef;
+                use $crate::base::{TCFType, TCFTypeRef};
                 self.as_concrete_TypeRef().as_void_ptr()
             }
         }
 
-        unsafe impl $crate::base::ToVoid<$ty> for $ty {
+        #[allow(unused_imports)]
+        unsafe impl<$($p $(: $bound)*),*> $crate::base::ToVoid<$ty<$($p),*>> for $ty<$($p),*> {
             fn to_void(&self) -> *const ::core::ffi::c_void {
-                use $crate::base::TCFTypeRef;
+                use $crate::base::{TCFType, TCFTypeRef};
                 self.as_concrete_TypeRef().as_void_ptr()
             }
         }
 
-        unsafe impl $crate::base::ToVoid<$ty> for $ty_ref {
+        #[allow(unused_imports)]
+        unsafe impl<$($p $(: $bound)*),*> $crate::base::ToVoid<$ty<$($p),*>> for $ty_ref {
             fn to_void(&self) -> *const ::core::ffi::c_void {
                 use $crate::base::TCFTypeRef;
                 self.as_void_ptr()
@@ -178,8 +196,10 @@ macro_rules! impl_CFTypeDescription {
         impl_CFTypeDescription!($ty<>);
     };
     ($ty:ident<$($p:ident $(: $bound:path)*),*>) => {
+        #[allow(unused_imports)]
         impl<$($p $(: $bound)*),*> ::std::fmt::Debug for $ty<$($p),*> {
             fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+                use $crate::base::TCFType;
                 self.as_CFType().fmt(f)
             }
         }
@@ -189,9 +209,12 @@ macro_rules! impl_CFTypeDescription {
 #[macro_export]
 macro_rules! impl_CFComparison {
     ($ty:ident, $compare:ident) => {
-        impl PartialOrd for $ty {
+        impl_CFComparison!($ty<>, $compare);
+    };
+    ($ty:ident<$($p:ident $(: $bound:path)*),*>, $compare:ident) => {
+        impl<$($p $(: $bound)*),*> PartialOrd for $ty<$($p),*> {
             #[inline]
-            fn partial_cmp(&self, other: &$ty) -> Option<::std::cmp::Ordering> {
+            fn partial_cmp(&self, other: &$ty<$($p),*>) -> Option<::std::cmp::Ordering> {
                 unsafe {
                     Some(
                         $compare(
@@ -205,9 +228,9 @@ macro_rules! impl_CFComparison {
             }
         }
 
-        impl Ord for $ty {
+        impl<$($p $(: $bound)*),*> Ord for $ty<$($p),*> {
             #[inline]
-            fn cmp(&self, other: &$ty) -> ::std::cmp::Ordering {
+            fn cmp(&self, other: &$ty<$($p),*>) -> ::std::cmp::Ordering {
                 self.partial_cmp(other).unwrap()
             }
         }

core-foundation/tests/use_macro_outside_crate.rs

@@ -24,3 +24,8 @@ declare_TCFType!(CFFooBar, CFFooBarRef);
 impl_TCFType!(CFFooBar, CFFooBarRef, CFFooBarGetTypeID);
 impl_CFTypeDescription!(CFFooBar);
 impl_CFComparison!(CFFooBar, fake_compare);
+
+declare_TCFType!(CFGenericFooBar<T: Clone>, CFFooBarRef);
+impl_TCFType!(CFGenericFooBar<T: Clone>, CFFooBarRef, CFFooBarGetTypeID);
+impl_CFTypeDescription!(CFGenericFooBar<T: Clone>);
+impl_CFComparison!(CFGenericFooBar<T: Clone>, fake_compare);