Cast for argument to delete[] - VC6 doesn't want to delete a const pointer

[wxWidgets.git] / include / wx / vector.h

diff --git a/include/wx/vector.h b/include/wx/vector.h
index 3d983aab196d8fa256f5439324bcfb69b90e94f3..85d925794371ef7e0b162d2def26a4ce7eaf8823 100644 (file)
--- a/include/wx/vector.h
+++ b/include/wx/vector.h
@@ -22,10 +22,99 @@
 #else // !wxUSE_STL
 
 #include "wx/utils.h"
 #else // !wxUSE_STL
 
 #include "wx/utils.h"

+#include "wx/meta/movable.h"
+#include "wx/meta/if.h"
+
+#include "wx/beforestd.h"
+#include <new> // for placement new
+#include "wx/afterstd.h"
+
+namespace wxPrivate
+{
+
+// These templates encapsulate memory operations for use by wxVector; there are
+// two implementations, both in generic way for any C++ types and as an
+// optimized version for "movable" types that uses realloc() and memmove().
+
+// version for movable types:
+template<typename T>
+struct wxVectorMemOpsMovable
+{
+    static void Free(T* array)
+        { free(array); }
+
+    static T* Realloc(T* old, size_t newCapacity, size_t WXUNUSED(occupiedSize))
+        { return (T*)realloc(old, newCapacity * sizeof(T)); }
+
+    static void MemmoveBackward(T* dest, T* source, size_t count)
+        { memmove(dest, source, count * sizeof(T)); }
+
+    static void MemmoveForward(T* dest, T* source, size_t count)
+        { memmove(dest, source, count * sizeof(T)); }
+};
+
+// generic version for non-movable types:
+template<typename T>
+struct wxVectorMemOpsGeneric
+{
+    static void Free(T* array)
+        { ::operator delete(array); }
+
+    static T* Realloc(T* old, size_t newCapacity, size_t occupiedSize)
+    {
+        T *mem = (T*)::operator new(newCapacity * sizeof(T));
+        for ( size_t i = 0; i < occupiedSize; i++ )
+        {
+            new(mem + i) T(old[i]);
+            old[i].~T();
+        }
+        ::operator delete(old);
+        return mem;
+    }
+
+    static void MemmoveBackward(T* dest, T* source, size_t count)
+    {
+        wxASSERT( dest < source );
+        T* destptr = dest;
+        T* sourceptr = source;
+        for ( size_t i = count; i > 0; --i, ++destptr, ++sourceptr )
+        {
+            new(destptr) T(*sourceptr);
+            sourceptr->~T();
+        }
+    }
+
+    static void MemmoveForward(T* dest, T* source, size_t count)
+    {
+        wxASSERT( dest > source );
+        T* destptr = dest + count - 1;
+        T* sourceptr = source + count - 1;
+        for ( size_t i = count; i > 0; --i, --destptr, --sourceptr )
+        {
+            new(destptr) T(*sourceptr);
+            sourceptr->~T();
+        }
+    }
+};
+
+
+} // namespace wxPrivate

 
 template<typename T>
 class wxVector
 {
 
 template<typename T>
 class wxVector
 {

+private:
+    // This cryptic expression means "typedef Ops to wxVectorMemOpsMovable if
+    // type T is movable type, otherwise to wxVectorMemOpsGeneric".
+    //
+    // Note that we use typedef instead of privately deriving from this (which
+    // would allowed us to omit "Ops::" prefixes below) to keep VC6 happy,
+    // it can't compile code that derives from wxIf<...>::value.
+    typedef typename wxIf< wxIsMovable<T>::value,
+                           wxPrivate::wxVectorMemOpsMovable<T>,
+                           wxPrivate::wxVectorMemOpsGeneric<T> >::value
+            Ops;
+

 public:
     typedef size_t size_type;
     typedef T value_type;
 public:
     typedef size_t size_type;
     typedef T value_type;


@@ -47,7 +136,13 @@ public:
 
     void clear()
     {
 
     void clear()
     {

-        delete[] m_values;
+        // call destructors of stored objects:
+        for ( size_type i = 0; i < m_size; i++ )
+        {
+            m_values[i].~T();
+        }
+
+        Ops::Free(m_values);

         m_values = NULL;
         m_size = m_capacity = 0;
     }
         m_values = NULL;
         m_size = m_capacity = 0;
     }


@@ -59,22 +154,16 @@ public:
 
         // increase the size twice, unless we're already too big or unless
         // more is requested
 
         // increase the size twice, unless we're already too big or unless
         // more is requested

-        const size_type increment = (m_size > 0)
-                                     ? wxMin(m_size, ALLOC_MAX_SIZE)
-                                     : ALLOC_INITIAL_SIZE;
+        //
+        // NB: casts to size_type are needed to suppress mingw32 warnings about
+        //     mixing enums and ints in the same expression
+        const size_type increment = m_size > 0
+                                     ? wxMin(m_size, (size_type)ALLOC_MAX_SIZE)
+                                     : (size_type)ALLOC_INITIAL_SIZE;

         if ( m_capacity + increment > n )
             n = m_capacity + increment;
 
         if ( m_capacity + increment > n )
             n = m_capacity + increment;
 

-        value_type *mem = new value_type[n];
-
-        if ( m_values )
-        {
-            for ( size_type i = 0; i < m_size; ++i )
-                mem[i] = m_values[i];
-            delete[] m_values;
-        }
-
-        m_values = mem;
+        m_values = Ops::Realloc(m_values, n * sizeof(value_type), m_size);

         m_capacity = n;
     }
 
         m_capacity = n;
     }
 


@@ -102,7 +191,17 @@ public:
     void push_back(const value_type& v)
     {
         reserve(size() + 1);
     void push_back(const value_type& v)
     {
         reserve(size() + 1);

-        m_values[m_size++] = v;
+
+        // use placement new to initialize new object in preallocated place in
+        // m_values and store 'v' in it:
+        void* const place = m_values + m_size;
+        new(place) value_type(v);
+
+        // only increase m_size if the ctor didn't throw an exception; notice
+        // that if it _did_ throw, everything is OK, because we only increased
+        // vector's capacity so far and possibly written some data to
+        // uninitialized memory at the end of m_values
+        m_size++;

     }
 
     void pop_back()
     }
 
     void pop_back()


@@ -136,16 +235,46 @@ public:
 
     iterator insert(iterator it, const value_type& v = value_type())
     {
 
     iterator insert(iterator it, const value_type& v = value_type())
     {

-        size_t idx = it - begin();
+        // NB: this must be done before reserve(), because reserve()
+        //     invalidates iterators!
+        const size_t idx = it - begin();
+        const size_t after = end() - it;

 
         reserve(size() + 1);
 
 
         reserve(size() + 1);
 

-        // unless we're inserting at the end, move following values out of
+        // unless we're inserting at the end, move following elements out of

         // the way:
         // the way:

-        for ( size_t n = m_size; n != idx; --n )
-            m_values[n] = m_values[n-1];
+        if ( after > 0 )
+        {
+            Ops::MemmoveForward(m_values + idx + 1, m_values + idx, after);
+        }

 
 

-        m_values[idx] = v;
+#if wxUSE_EXCEPTIONS
+        try
+        {
+#endif
+            // use placement new to initialize new object in preallocated place
+            // in m_values and store 'v' in it:
+            void* const place = m_values + idx;
+            new(place) value_type(v);
+#if wxUSE_EXCEPTIONS
+        }
+        catch ( ... )
+        {
+            // if the ctor threw an exception, we need to move all the elements
+            // back to their original positions in m_values
+            if ( after > 0 )
+            {
+                Ops::MemmoveBackward(m_values + idx, m_values + idx + 1, after);
+            }
+
+            throw; // rethrow the exception
+        }
+#endif // wxUSE_EXCEPTIONS
+
+        // increment m_size only if ctor didn't throw -- if it did, we'll be
+        // left with m_values larger than necessary, but number of elements will
+        // be the same

         m_size++;
 
         return begin() + idx;
         m_size++;
 
         return begin() + idx;


@@ -162,20 +291,23 @@ public:
             return first;
         wxASSERT( first < end() && last <= end() );
 
             return first;
         wxASSERT( first < end() && last <= end() );
 

-        size_type index = first - begin();
-        size_type count = last - first;
+        const size_type idx = first - begin();
+        const size_type count = last - first;
+        const size_type after = end() - last;

 
 

-        // move the remaining values over to the freed space:
-        for ( iterator i = last; i < end(); ++i )
-            *(i - count) = *i;
+        // erase elements by calling their destructors:
+        for ( iterator i = first; i < last; ++i )
+            i->~T();

 
 

-        // erase items behind the new end of m_values:
-        for ( iterator i = end() - count; i < end(); ++i )
-            *i = value_type();
+        // once that's done, move following elements over to the freed space:
+        if ( after > 0 )
+        {
+            Ops::MemmoveBackward(m_values + idx, m_values + idx + count, after);
+        }

 
         m_size -= count;
 
 
         m_size -= count;
 

-        return begin() + index;
+        return begin() + idx;

     }
 
 #if WXWIN_COMPATIBILITY_2_8
     }
 
 #if WXWIN_COMPATIBILITY_2_8


@@ -204,7 +336,7 @@ private:
 
 #if WXWIN_COMPATIBILITY_2_8
 template<typename T>
 
 #if WXWIN_COMPATIBILITY_2_8
 template<typename T>

-typename wxVector<T>::size_type wxVector<T>::erase(size_type n)
+inline typename wxVector<T>::size_type wxVector<T>::erase(size_type n)

 {
     erase(begin() + n);
     return n;
 {
     erase(begin() + n);
     return n;