New upstream version 1.22.1+dfsg1

[rustc.git] / src / librustc_data_structures / indexed_vec.rs

diff --git a/src/librustc_data_structures/indexed_vec.rs b/src/librustc_data_structures/indexed_vec.rs
index bc9bfa4049723fccdce3fc7aef4277a455a8b1d9..4b7f55eba06bec1ced8564273b7f5d3e7c3cfad5 100644 (file)
--- a/src/librustc_data_structures/indexed_vec.rs
+++ b/src/librustc_data_structures/indexed_vec.rs
@@ -38,7 +38,44 @@ impl Idx for u32 {
     fn index(self) -> usize { self as usize }
 }
 
-#[derive(Clone)]
+#[macro_export]
+macro_rules! newtype_index {
+    ($name:ident) => (
+        newtype_index!($name, unsafe { ::std::intrinsics::type_name::<$name>() });
+    );
+
+    ($name:ident, $debug_name:expr) => (
+        #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord,
+         RustcEncodable, RustcDecodable)]
+        pub struct $name(u32);
+
+        impl $name {
+            // HACK use for constants
+            #[allow(unused)]
+            const fn const_new(x: u32) -> Self {
+                $name(x)
+            }
+        }
+
+        impl Idx for $name {
+            fn new(value: usize) -> Self {
+                assert!(value < (::std::u32::MAX) as usize);
+                $name(value as u32)
+            }
+            fn index(self) -> usize {
+                self.0 as usize
+            }
+        }
+
+        impl ::std::fmt::Debug for $name {
+            fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+                write!(fmt, "{}{}", $debug_name, self.0)
+            }
+        }
+    )
+}
+
+#[derive(Clone, PartialEq, Eq)]
 pub struct IndexVec<I: Idx, T> {
     pub raw: Vec<T>,
     _marker: PhantomData<Fn(&I)>