X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;ds=sidebyside;f=src%2Flibrustc_data_structures%2Fmacros.rs;h=67fbe3058cdb981170ce653c9d22c0695f8f753c;hb=5e9888eec5f5e5d41be0d6ccd0b55bbd536f44e9;hp=3f75523a81584a7bc62330d01ab267200f68ec75;hpb=88629778e6faeda18409ffaa9a00291e3605bae3;p=rust.git

diff --git a/src/librustc_data_structures/macros.rs b/src/librustc_data_structures/macros.rs
index 3f75523a815..67fbe3058cd 100644
--- a/src/librustc_data_structures/macros.rs
+++ b/src/librustc_data_structures/macros.rs
@@ -7,7 +7,7 @@ macro_rules! static_assert {
         // is out-of-bounds.
         #[allow(dead_code)]
         const _: () = [()][!($test: bool) as usize];
-    }
+    };
 }
 
 /// Type size assertion. The first argument is a type and the second argument is its expected size.
@@ -15,5 +15,43 @@ macro_rules! static_assert {
 macro_rules! static_assert_size {
     ($ty:ty, $size:expr) => {
         const _: [(); $size] = [(); ::std::mem::size_of::<$ty>()];
+    };
+}
+
+#[macro_export]
+macro_rules! enum_from_u32 {
+    ($(#[$attr:meta])* pub enum $name:ident {
+        $($variant:ident = $e:expr,)*
+    }) => {
+        $(#[$attr])*
+        pub enum $name {
+            $($variant = $e),*
+        }
+
+        impl $name {
+            pub fn from_u32(u: u32) -> Option<$name> {
+                $(if u == $name::$variant as u32 {
+                    return Some($name::$variant)
+                })*
+                None
+            }
+        }
+    };
+    ($(#[$attr:meta])* pub enum $name:ident {
+        $($variant:ident,)*
+    }) => {
+        $(#[$attr])*
+        pub enum $name {
+            $($variant,)*
+        }
+
+        impl $name {
+            pub fn from_u32(u: u32) -> Option<$name> {
+                $(if u == $name::$variant as u32 {
+                    return Some($name::$variant)
+                })*
+                None
+            }
+        }
     }
 }