_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

_com_error

Constructs a _com_error object.

Operators

operator =

Assigns an existing _com_error object to another.

Extractor Functions

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

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

ErrorMessage

Retrieves the string message for HRESULT stored in the _com_error object.

ExepInfo.wCode to HRESULT Mappers

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

Requirements

Header: comdef.h

Lib: comsuppw.lib or comsuppwd.lib (see /Zc:wchar_t (wchar_t Is Native Type) for more information)

See Also

Reference

Compiler COM Support Classes

IErrorInfo Interface

Change History

Date	History	Reason
December 2008	Linked to the "IErrorInfo Interface" topic. Updated formatting.	Customer feedback.