From: Howard Hinnant <hhinnant@apple.com>
Date: Thu, 28 Mar 2013 15:47:50 +0000 (+0000)
Subject: Seciton 24.2.2 of the C++ standard, [iterator.iterators], Table 106
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=aab230545459fea4204d7e8a82e93109ebaa880f;p=oota-llvm.git

Seciton 24.2.2 of the C++ standard, [iterator.iterators], Table 106
requires that the return type of *r for all iterators r be reference,
where reference is defined in [iterator.requirements.general]/p11 as
iterator_traits<X>::reference, and X is the type of r.

But in CFG.h, the dereference operator of PredIterator and SuccIterator
return pointer, not reference.

Furthermore the nested type reference is value_type&, which is not the
type returned from operator*().

This patch simply makes the iterator::reference type value_type*, which
is what the operator*() returns, and then re-lables the return type as
reference.

From a functionality point of view, the only difference is that the
nested reference type is now value_type* instead of value_type&.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178240 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Support/CFG.h b/include/llvm/Support/CFG.h
index a9fb65cba90..265b886daff 100644
--- a/include/llvm/Support/CFG.h
+++ b/include/llvm/Support/CFG.h
@@ -27,8 +27,9 @@ namespace llvm {
 
 template <class Ptr, class USE_iterator> // Predecessor Iterator
 class PredIterator : public std::iterator<std::forward_iterator_tag,
-                                          Ptr, ptrdiff_t> {
-  typedef std::iterator<std::forward_iterator_tag, Ptr, ptrdiff_t> super;
+                                          Ptr, ptrdiff_t, Ptr*, Ptr*> {
+  typedef std::iterator<std::forward_iterator_tag, Ptr, ptrdiff_t, Ptr*,
+                                                                    Ptr*> super;
   typedef PredIterator<Ptr, USE_iterator> Self;
   USE_iterator It;
 
@@ -40,6 +41,7 @@ class PredIterator : public std::iterator<std::forward_iterator_tag,
 
 public:
   typedef typename super::pointer pointer;
+  typedef typename super::reference reference;
 
   PredIterator() {}
   explicit inline PredIterator(Ptr *bb) : It(bb->use_begin()) {
@@ -50,7 +52,7 @@ public:
   inline bool operator==(const Self& x) const { return It == x.It; }
   inline bool operator!=(const Self& x) const { return !operator==(x); }
 
-  inline pointer operator*() const {
+  inline reference operator*() const {
     assert(!It.atEnd() && "pred_iterator out of range!");
     return cast<TerminatorInst>(*It)->getParent();
   }
@@ -100,10 +102,11 @@ inline const_pred_iterator pred_end(const BasicBlock *BB) {
 
 template <class Term_, class BB_>           // Successor Iterator
 class SuccIterator : public std::iterator<std::bidirectional_iterator_tag,
-                                          BB_, ptrdiff_t> {
+                                          BB_, ptrdiff_t, BB_*, BB_*> {
   const Term_ Term;
   unsigned idx;
-  typedef std::iterator<std::bidirectional_iterator_tag, BB_, ptrdiff_t> super;
+  typedef std::iterator<std::bidirectional_iterator_tag, BB_, ptrdiff_t, BB_*,
+                                                                    BB_*> super;
   typedef SuccIterator<Term_, BB_> Self;
 
   inline bool index_is_valid(int idx) {
@@ -112,6 +115,7 @@ class SuccIterator : public std::iterator<std::bidirectional_iterator_tag,
 
 public:
   typedef typename super::pointer pointer;
+  typedef typename super::reference reference;
   // TODO: This can be random access iterator, only operator[] missing.
 
   explicit inline SuccIterator(Term_ T) : Term(T), idx(0) {// begin iterator
@@ -142,7 +146,7 @@ public:
   inline bool operator==(const Self& x) const { return idx == x.idx; }
   inline bool operator!=(const Self& x) const { return !operator==(x); }
 
-  inline pointer operator*() const { return Term->getSuccessor(idx); }
+  inline reference operator*() const { return Term->getSuccessor(idx); }
   inline pointer operator->() const { return operator*(); }
 
   inline Self& operator++() { ++idx; return *this; } // Preincrement