Calculates a hash value for the given key.
template<class ARG_KEY>
AFX_INLINE UINT AFXAPI HashKey(
   ARG_KEY key 
);
Parameters
- ARG_KEY 
 Template parameter specifying the data type used to access map keys.
- key 
 The key whose hash value is to be calculated.
Return Value
The key's hash value.
Remarks
This function is called directly by CMap::RemoveKey and indirectly by CMap::Lookup and CMap::Operator [].
The default implementation creates a hash value by shifting key right by four positions. Override this function so that it returns hash values appropriate for your application.
Example
template <> UINT AFXAPI HashKey(unsigned __int64 key)
{
   // Generate the hash value by XORing the lower 32 bits of the number 
   // with the upper 32 bits
   return(UINT(key) ^ UINT(key >> 32));
}
Requirements
Header: afxtempl.h