---
description: "Learn more about: _com_error::_com_error"
title: "_com_error::_com_error"
ms.date: 11/17/2022
f1_keywords: ["COMDEF/_com_error", "_com_error::_com_error"]
helpviewer_keywords: ["_com_error constructor [C++]"]
ms.assetid: 0a69e46c-caab-49ef-b091-eee401253ce6
---
# `_com_error::_com_error`

**Microsoft Specific**

Constructs a `_com_error` object.

## Syntax

```cpp
_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.

*`fAddRef`*\
The default causes the constructor to not call AddRef on a non-null `IErrorInfo` interface. This behavior provides for correct reference counting in the common case where ownership of the interface is passed into the `_com_error` object, such as:

```cpp
throw _com_error(hr, perrinfo);
```

If you don't 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:

```cpp
_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)