Remove Restriction

The Restriction struct now consists of a single Rc<LoanPath> field, so
it can be replaced with Rc<LoanPath>.

Author: Cameron Zwarich

src/librustc/middle/borrowck/check_loans.rs

@@ -208,8 +208,8 @@ impl<'a> CheckLoanCtxt<'a> {
                    loan.repr(self.tcx()));
 
             let mut ret = true;
-            for restr in loan.restrictions.iter() {
-                if *restr.loan_path == *loan_path {
+            for restr_path in loan.restricted_paths.iter() {
+                if **restr_path == *loan_path {
                     if !op(loan) {
                         ret = false;
                         break;
@@ -298,8 +298,8 @@ impl<'a> CheckLoanCtxt<'a> {
             return true;
         }
 
-        for restr in loan1.restrictions.iter() {
-            if restr.loan_path != loan2.loan_path { continue; }
+        for restr_path in loan1.restricted_paths.iter() {
+            if *restr_path != loan2.loan_path { continue; }
 
             let old_pronoun = if new_loan.loan_path == old_loan.loan_path {
                 "it".to_string()

src/librustc/middle/borrowck/gather_loans/mod.rs

@@ -268,7 +268,7 @@ impl<'a> GatherLoanCtxt<'a> {
                 return;
             }
 
-            restrictions::SafeIf(loan_path, restrictions) => {
+            restrictions::SafeIf(loan_path, restricted_paths) => {
                 let loan_scope = match loan_region {
                     ty::ReScope(id) => id,
                     ty::ReFree(ref fr) => fr.scope_id,
@@ -314,7 +314,7 @@ impl<'a> GatherLoanCtxt<'a> {
                     gen_scope: gen_scope,
                     kill_scope: kill_scope,
                     span: borrow_span,
-                    restrictions: restrictions,
+                    restricted_paths: restricted_paths,
                     cause: cause,
                 }
             }

src/librustc/middle/borrowck/gather_loans/restrictions.rs

@@ -23,7 +23,7 @@ use std::rc::Rc;
 
 pub enum RestrictionResult {
     Safe,
-    SafeIf(Rc<LoanPath>, Vec<Restriction>)
+    SafeIf(Rc<LoanPath>, Vec<Rc<LoanPath>>)
 }
 
 pub fn compute_restrictions(bccx: &BorrowckCtxt,
@@ -71,7 +71,7 @@ impl<'a> RestrictionsContext<'a> {
             mc::cat_upvar(ty::UpvarId {var_id: local_id, ..}, _) => {
                 // R-Variable
                 let lp = Rc::new(LpVar(local_id));
-                SafeIf(lp.clone(), vec!(Restriction { loan_path: lp }))
+                SafeIf(lp.clone(), vec!(lp))
             }
 
             mc::cat_downcast(cmt_base) => {
@@ -164,7 +164,7 @@ impl<'a> RestrictionsContext<'a> {
             Safe => Safe,
             SafeIf(base_lp, mut base_vec) => {
                 let lp = Rc::new(LpExtend(base_lp, mc, elem));
-                base_vec.push(Restriction { loan_path: lp.clone() });
+                base_vec.push(lp.clone());
                 SafeIf(lp, base_vec)
             }
         }

src/librustc/middle/borrowck/mod.rs

@@ -181,7 +181,7 @@ pub struct Loan {
     index: uint,
     loan_path: Rc<LoanPath>,
     kind: ty::BorrowKind,
-    restrictions: Vec<Restriction>,
+    restricted_paths: Vec<Rc<LoanPath>>,
     gen_scope: ast::NodeId,
     kill_scope: ast::NodeId,
     span: Span,
@@ -249,10 +249,6 @@ pub fn opt_loan_path(cmt: &mc::cmt) -> Option<Rc<LoanPath>> {
     }
 }
 
-pub struct Restriction {
-    loan_path: Rc<LoanPath>,
-}
-
 ///////////////////////////////////////////////////////////////////////////
 // Errors
 
@@ -777,13 +773,7 @@ impl Repr for Loan {
                  self.kind,
                  self.gen_scope,
                  self.kill_scope,
-                 self.restrictions.repr(tcx))).to_string()
-    }
-}
-
-impl Repr for Restriction {
-    fn repr(&self, tcx: &ty::ctxt) -> String {
-        (format!("Restriction({})", self.loan_path.repr(tcx))).to_string()
+                 self.restricted_paths.repr(tcx))).to_string()
     }
 }