---
title: "_com_error Class"
ms.date: "11/04/2016"
f1_keywords: ["_com_error"]
helpviewer_keywords: ["_com_error class"]
ms.assetid: 70dafa69-b1fb-4a5c-9249-e857e0793d42
---
# _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

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|[_com_error](../cpp/com-error-com-error.md)|Constructs a **_com_error** object.|

### Operators

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|[operator =](../cpp/com-error-operator-equal.md)|Assigns an existing **_com_error** object to another.|

### Extractor Functions

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|[Error](../cpp/com-error-error.md)|Retrieves the HRESULT passed to the constructor.|
|[ErrorInfo](../cpp/com-error-errorinfo.md)|Retrieves the `IErrorInfo` object passed to the constructor.|
|[WCode](../cpp/com-error-wcode.md)|Retrieves the 16-bit error code mapped into the encapsulated HRESULT.|

### IErrorInfo Functions

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|[Description](../cpp/com-error-description.md)|Calls `IErrorInfo::GetDescription` function.|
|[HelpContext](../cpp/com-error-helpcontext.md)|Calls `IErrorInfo::GetHelpContext` function.|
|[HelpFile](../cpp/com-error-helpfile.md)|Calls `IErrorInfo::GetHelpFile` function|
|[Source](../cpp/com-error-source.md)|Calls `IErrorInfo::GetSource` function.|
|[GUID](../cpp/com-error-guid.md)|Calls `IErrorInfo::GetGUID` function.|

### Format Message Extractor

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|[ErrorMessage](../cpp/com-error-errormessage.md)|Retrieves the string message for HRESULT stored in the **_com_error** object.|

### ExepInfo.wCode to HRESULT Mappers

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|[HRESULTToWCode](../cpp/com-error-hresulttowcode.md)|Maps 32-bit HRESULT to 16-bit `wCode`.|
|[WCodeToHRESULT](../cpp/com-error-wcodetohresult.md)|Maps 16-bit `wCode` to 32-bit HRESULT.|

**END Microsoft Specific**

## Requirements

**Header:** \<comdef.h>

`Lib:` comsuppw.lib or comsuppwd.lib (see [/Zc:wchar_t (wchar_t Is Native Type)](../build/reference/zc-wchar-t-wchar-t-is-native-type.md) for more information)

## See also

[Compiler COM Support Classes](../cpp/compiler-com-support-classes.md)<br/>
[IErrorInfo Interface](/windows/win32/api/oaidl/nn-oaidl-ierrorinfo)