#include "wx/utils.h"
+#include "wx/beforestd.h"
+#include <new> // for placement new
+#include "wx/afterstd.h"
+
template<typename T>
class wxVector
{
void clear()
{
- delete[] m_values;
+ // call destructors of stored objects:
+ for ( size_type i = 0; i < m_size; i++ )
+ {
+ m_values[i].~T();
+ }
+
+ free(m_values);
m_values = NULL;
m_size = m_capacity = 0;
}
// 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;
- 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 = (value_type*)realloc(m_values, n * sizeof(value_type));
- m_values = mem;
m_capacity = n;
}
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 )
+ {
+ memmove(m_values + idx + 1,
+ m_values + idx,
+ after * sizeof(value_type));
+ }
+
+#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 )
+ {
+ memmove(m_values + idx,
+ m_values + idx + 1,
+ after * sizeof(value_type));
+ }
+
+ 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->~value_type();
- // 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 )
+ {
+ memmove(m_values + idx,
+ m_values + idx + count,
+ after * sizeof(value_type));
+ }
m_size -= count;
- return begin() + index;
+ return begin() + idx;
}
#if WXWIN_COMPATIBILITY_2_8
#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;