C6226

warning C6226: Implicit cast between semantically different integer types: assigning -1 to HRESULT. Consider using E_FAIL instead.

This warning indicates that an HRESULT is assigned or initialized to an explicit value of -1. This warning is frequently caused by accidental confusion of integer and HRESULT types. To indicate success, use the symbolic constant S_OK instead. To indicate failure, use the symbolic constants that start with E_constant, such as E_FAIL.

For more information, see the SUCCEEDED and FAILED macros.

Example

The following code generates this warning:

#include <windows.h>

VOID f( )
{
  HRESULT hr;
  LPMALLOC pMalloc;

  if (FAILED(CoGetMalloc(1, &pMalloc)))
  {
    hr = -1;
    // code ...
  }
  else
  {
    // code ...
  }
}

To correct this warning, use the following code:

#include <windows.h>

VOID f( )
{
  HRESULT hr;
  LPMALLOC pMalloc;

  if (FAILED(CoGetMalloc(1, &pMalloc)))
  {
    hr = E_FAIL;
    // code ...
  }
  else
  {
    // code ...
  }
}

For this warning, the SCODE type is treated as an HRESULT.

The use of malloc and free (and related dynamic memory APIs) has many pitfalls as a cause of memory leaks and exceptions. To avoid these kinds of leaks and exception problems, use the pointer and container classes provided by the C++ Standard Library. These include shared_ptr, unique_ptr, and vector. For more information, see Smart Pointers and C++ Standard Library.