---
title: "_com_error::_com_error | Microsoft Docs"
ms.custom: ""
ms.date: "11/04/2016"
ms.technology: ["cpp-language"]
ms.topic: "language-reference"
f1_keywords: ["_com_error::_com_error"]
dev_langs: ["C++"]
helpviewer_keywords: ["_com_error method [C++]"]
ms.assetid: 0a69e46c-caab-49ef-b091-eee401253ce6
author: "mikeblome"
ms.author: "mblome"
ms.workload: ["cplusplus"]
---
# _com_error::_com_error
**Microsoft Specific**  
  
 Constructs a `_com_error` object.  
  
## Syntax  
  
```  
  
      _com_error(  
   HRESULT hr,  
   IErrorInfo* perrinfo = NULL,  
   bool fAddRef=false  
) throw( );  
_com_error(  
   const _com_error& that   
) throw( );  
```  
  
#### Parameters  
 `hr`  
 `HRESULT` information.  
  
 `perrinfo`  
 **IErrorInfo** object.  
  
 **bool fAddRef=false**  
 Causes the constructor to call AddRef on a non-null **IErrorInfo** interface. This provides for correct reference counting in the common case where ownership of the interface is passed into the `_com_error` object, such as:  
  
```  
throw _com_error(hr, perrinfo);  
```  
  
 If you do not want your code to transfer ownership to the `_com_error` object, and the `AddRef` is required to offset the **Release** in the `_com_error` destructor, construct the object as follows:  
  
```  
_com_error err(hr, perrinfo, true);  
```  
  
 `that`  
 An existing `_com_error` object.  
  
## Remarks  
 The first constructor creates a new object given an `HRESULT` and optional **IErrorInfo** object. The second creates a copy of an existing `_com_error` object.  
  
 **END Microsoft Specific**  
  
## See Also  
 [_com_error Class](../cpp/com-error-class.md)