C / C++ / MFC

Ajay L D wrote:

WriteFile(fpNew, str, sizeof(str), &dwNumBytesWritten, NULL);

WriteFile(fpNew, str, dwNumBytesRead, &dwNumBytesWritten, NULL);

George_George wrote:

1. whether or not we are using auto_ptr to allocate new object on heap (using new), there may be bad_alloc exceptions;

George_George wrote:

when we met with such exceptions, we catch it (bad_alloc)

George_George wrote:

and try to mininize the operation in catch handler block (since when bad_alloc occurs, it means memory is running out, we can not do anything complex in handler).

George_George wrote:

If we met with bad_alloc, do we need to use delete or delete[] to free the memory in exception handler block?

George_George wrote:

But I think it is not implemented in Visual Studio, right?

George_George wrote:

any comments/options about our original question (put your good ideas about shared_ptr aside for a while)? Is my understanding correct?

template <typename t="">
class ScopePtr
{
   T * m_pT;
 public:
   ScopePtr(T * pT) : m_pT(pT) {}
  ~ScopePtr() { delete m_pT; }
   T * ptr() { return m_pT; }
}
</typename>

void Foo()
{
  ScopePtr<bar> bar(new Bar()); // instead of Bar * bar = new Bar();
  bar.ptr()->Run(); // instead of bar->Run();
  ...         
}
</bar>

BSTR temp = 0;
HRESULT hr = get_Path(&temp);
// TODO: handle errors here
m_bstrNewPath.Attach(temp);

_bstr_t path = ...; // from whereever

BSTR temp = path.Detach();
HRESULT hr = comObject->ModifyPath(&temp);
path.Attach(temp);
if (FAILED(hr))
{
  // handle error here
}