Implement a proper iterator for QTypedArrayData

This avoids ambiguities in our API when someone e.g. writes
vector.insert(0, ...).

It requires a slight workaround in qlalr, where std::search()
for libc++ doesn't like that our difference_type is qsizetype.

Change-Id: I40aa1040781ffbdd12d04410078207969b3bde53
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 68 insertions, 4 deletions

diff --git a/src/corelib/tools/qarraydata.h b/src/corelib/tools/qarraydata.h
index b66a5add04..c1f9656707 100644
--- a/src/corelib/tools/qarraydata.h
+++ b/src/corelib/tools/qarraydata.h
@@ -133,8 +133,72 @@ template <class T>
 struct QTypedArrayData
     : QArrayData
 {
-    typedef T* iterator;
-    typedef const T* const_iterator;
+    class iterator {
+        T *i = nullptr;
+    public:
+        typedef std::random_access_iterator_tag  iterator_category;
+        typedef qsizetype difference_type;
+        typedef T value_type;
+        typedef T *pointer;
+        typedef T &reference;
+
+        inline constexpr iterator() = default;
+        inline iterator(T *n) : i(n) {}
+        inline T &operator*() const { return *i; }
+        inline T *operator->() const { return i; }
+        inline T &operator[](qsizetype j) const { return *(i + j); }
+        inline constexpr bool operator==(iterator o) const { return i == o.i; }
+        inline constexpr bool operator!=(iterator o) const { return i != o.i; }
+        inline constexpr bool operator<(iterator other) const { return i < other.i; }
+        inline constexpr bool operator<=(iterator other) const { return i <= other.i; }
+        inline constexpr bool operator>(iterator other) const { return i > other.i; }
+        inline constexpr bool operator>=(iterator other) const { return i >= other.i; }
+        inline iterator &operator++() { ++i; return *this; }
+        inline iterator operator++(int) { T *n = i; ++i; return n; }
+        inline iterator &operator--() { i--; return *this; }
+        inline iterator operator--(int) { T *n = i; i--; return n; }
+        inline iterator &operator+=(qsizetype j) { i+=j; return *this; }
+        inline iterator &operator-=(qsizetype j) { i-=j; return *this; }
+        inline iterator operator+(qsizetype j) const { return iterator(i+j); }
+        inline iterator operator-(qsizetype j) const { return iterator(i-j); }
+        friend inline iterator operator+(qsizetype j, iterator k) { return k + j; }
+        inline qsizetype operator-(iterator j) const { return i - j.i; }
+        inline operator T*() const { return i; }
+    };
+
+    class const_iterator {
+        const T *i = nullptr;
+    public:
+        typedef std::random_access_iterator_tag  iterator_category;
+        typedef qsizetype difference_type;
+        typedef T value_type;
+        typedef const T *pointer;
+        typedef const T &reference;
+
+        inline constexpr const_iterator() = default;
+        inline const_iterator(const T *n) : i(n) {}
+        inline constexpr const_iterator(iterator o): i(o) {}
+        inline const T &operator*() const { return *i; }
+        inline const T *operator->() const { return i; }
+        inline const T &operator[](qsizetype j) const { return *(i + j); }
+        inline bool operator==(const_iterator o) const { return i == o.i; }
+        inline bool operator!=(const_iterator o) const { return i != o.i; }
+        inline bool operator<(const_iterator other) const { return i < other.i; }
+        inline bool operator<=(const_iterator other) const { return i <= other.i; }
+        inline bool operator>(const_iterator other) const { return i > other.i; }
+        inline bool operator>=(const_iterator other) const { return i >= other.i; }
+        inline const_iterator &operator++() { ++i; return *this; }
+        inline const_iterator operator++(int) { const T *n = i; ++i; return n; }
+        inline const_iterator &operator--() { i--; return *this; }
+        inline const_iterator operator--(int) { const T *n = i; i--; return n; }
+        inline const_iterator &operator+=(qsizetype j) { i+=j; return *this; }
+        inline const_iterator &operator-=(qsizetype j) { i-=j; return *this; }
+        inline const_iterator operator+(qsizetype j) const { return const_iterator(i+j); }
+        inline const_iterator operator-(qsizetype j) const { return const_iterator(i-j); }
+        friend inline const_iterator operator+(qsizetype j, const_iterator k) { return k + j; }
+        inline qsizetype operator-(const_iterator j) const { return i - j.i; }
+        inline operator const T*() const { return i; }
+    };
 
     class AlignmentDummy { QArrayData header; T data; };
 
diff --git a/src/tools/qlalr/compress.cpp b/src/tools/qlalr/compress.cpp
index eb4ccdc783..ae0fbaca9d 100644
--- a/src/tools/qlalr/compress.cpp
+++ b/src/tools/qlalr/compress.cpp
@@ -186,7 +186,7 @@ void Compress::operator () (int *table, int row_count, int column_count)
           if (pos == info.begin ())
             {
               // try to find a perfect match
-              QList<int>::iterator pm = std::search(pos, info.end(), row.beginNonZeros(),
+              QList<int>::iterator pm = std::search(&*pos, &*info.end(), row.beginNonZeros(),
                                                     row.endNonZeros(), _PerfectMatch());
 
               if (pm != info.end ())
@@ -196,7 +196,7 @@ void Compress::operator () (int *table, int row_count, int column_count)
                 }
             }
 
-          pos = std::search (pos, info.end (), row.beginNonZeros (), row.endNonZeros (), _Fit ());
+          pos = std::search (&*pos, &*info.end (), row.beginNonZeros (), row.endNonZeros (), _Fit ());
 
           if (pos == info.end ())
             break;