_com_error class

Microsoft Specific

A _com_error object represents an exception condition detected by the error-handling wrapper functions in the header files generated from the type library or by one of the COM support classes. The _com_error class encapsulates the HRESULT error code and any associated IErrorInfo Interface object.

Construction

Name Description
_com_error Constructs a _com_error object.

Operators

Name Description
operator = Assigns an existing _com_error object to another.

Extractor functions

Name Description
Error Retrieves the HRESULT passed to the constructor.
ErrorInfo Retrieves the IErrorInfo object passed to the constructor.
WCode Retrieves the 16-bit error code mapped into the encapsulated HRESULT.

IErrorInfo functions

Name Description
Description Calls IErrorInfo::GetDescription function.
HelpContext Calls IErrorInfo::GetHelpContext function.
HelpFile Calls IErrorInfo::GetHelpFile function
Source Calls IErrorInfo::GetSource function.
GUID Calls IErrorInfo::GetGUID function.

Format message extractor

Name Description
ErrorMessage Retrieves the string message for HRESULT stored in the _com_error object.

ExepInfo.wCode to HRESULT mappers

Name Description
HRESULTToWCode Maps 32-bit HRESULT to 16-bit wCode.
WCodeToHRESULT Maps 16-bit wCode to 32-bit HRESULT.

END Microsoft Specific

Requirements

Header: <comdef.h>

Library: comsuppw.lib or comsuppwd.lib (for more information, see /Zc:wchar_t (wchar_t is native type))

See also

Compiler COM support classes
IErrorInfo interface