---
title: "_com_error Class | Microsoft Docs"
ms.custom: ""
ms.date: "11/04/2016"
ms.technology: ["cpp-language"]
ms.topic: "language-reference"
f1_keywords: ["_com_error"]
dev_langs: ["C++"]
helpviewer_keywords: ["_com_error class"]
ms.assetid: 70dafa69-b1fb-4a5c-9249-e857e0793d42
author: "mikeblome"
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---
# _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)   
 [IErrorInfo Interface](http://msdn.microsoft.com/en-us/4dda6909-2d9a-4727-ae0c-b5f90dcfa447)