Generate Idx in nll using newtype_index!

Author: spastorino

src/Cargo.lock

@@ -17,5 +17,6 @@ rustc_const_eval = { path = "../librustc_const_eval" }
 rustc_const_math = { path = "../librustc_const_math" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
+serialize = { path = "../libserialize" }
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }

src/librustc_mir/Cargo.toml

@@ -30,7 +30,8 @@ extern crate bitflags;
 extern crate graphviz as dot;
 #[macro_use]
 extern crate rustc;
-extern crate rustc_data_structures;
+#[macro_use] extern crate rustc_data_structures;
+extern crate serialize as rustc_serialize;
 extern crate rustc_errors;
 #[macro_use]
 extern crate syntax;

src/librustc_mir/lib.rs

@@ -19,6 +19,8 @@ use rustc::util::nodemap::FxHashSet;
 use rustc_data_structures::indexed_vec::{IndexVec, Idx};
 use syntax_pos::DUMMY_SP;
 use std::collections::HashMap;
+use std::fmt::{self, Debug, Formatter};
+use std::u32;
 
 #[allow(dead_code)]
 struct NLLVisitor<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
@@ -155,18 +157,4 @@ struct Region {
     points: FxHashSet<Location>,
 }
 
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Ord, PartialOrd, Debug)]
-pub struct RegionIndex(pub u32);
-
-impl Idx for RegionIndex {
-    #[inline]
-    fn new(idx: usize) -> Self {
-        assert!(idx <= ::std::u32::MAX as usize);
-        RegionIndex(idx as u32)
-    }
-
-    #[inline]
-    fn index(self) -> usize {
-        self.0 as usize
-    }
-}
+newtype_index!(RegionIndex, "region_index");