#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
{
+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;
wxVector() : m_size(0), m_capacity(0), m_values(NULL) {}
- wxVector(const wxVector& c)
+ wxVector(const wxVector& c) : m_size(0), m_capacity(0), m_values(NULL)
{
Copy(c);
}
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_size =
+ m_capacity = 0;
}
void reserve(size_type n)
// increase the size twice, unless we're already too big or unless
// more is requested
//
- // NB: casts to size_t are needed to suppress mingw32 warnings about
+ // 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)
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;
}
wxVector& operator=(const wxVector& vb)
{
+ clear();
Copy(vb);
return *this;
}
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()
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);
- // 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:
- 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);
+ }
+
+#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
- m_values[idx] = v;
+ // 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;
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 j = end() - count; j < end(); ++j )
- *j = 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;
- return begin() + index;
+ return begin() + idx;
}
#if WXWIN_COMPATIBILITY_2_8
void Copy(const wxVector& vb)
{
- clear();
reserve(vb.size());
for ( const_iterator i = vb.begin(); i != vb.end(); ++i )
projects / wxWidgets.git / blobdiff