---
name: "ACE_Command_Base"
section: "3"
platform: "linux"
package: "libace-doc"
version: "5.0.7-4"
release: "Debian 2.2 (Potato)"
platforms: ["linux"]
url: "https://new.carta.tech/ACE_Command_Base"
---

# ACE\_Command\_Base(3)

Defines an abstract class that allows us to invoke commands without knowing anything about the implementation.

## NAME

ACE\_Command\_Base -  Defines an abstract class that allows us to invoke commands without knowing anything about the implementation.

## SYNOPSIS

```
#include <ace/Functor.h>
class ACE_Command_Base
{
  public:
    ACE_Command_Base (void);
    virtual ~ACE_Command_Base (void);
    virtual int execute (void *arg = 0) = 0;
};
```

## DESCRIPTION

 Non-templatized classes and class template specializations for\
  implementing function objects that are used in  various places\
  in ACE.  There are currently two major categories of function\
  objects in ACE: GOF Command Pattern objects, and STL-style\
  functors for comparison of container elements.  The command objects\
  are invoked via an execute () method, while the STL-style functors are\
  invoked via an operator() () method. Non-templatized classes for implementing the GOF Command Pattern, also known as functors or function objects.

## Initialization and termination methods.

```
ACE_Command_Base (void);
```

Default constructor.

```
virtual ~ACE_Command_Base (void);
```

Virtaul destructor.

```
virtual int execute (void *arg = 0) = 0;
```

Invokes the method encapsulated by the command, passing along the passed argument (if any).  Users of classes derived from this class must ensure that the resulting invocation can tolerate a null void pointer being passed, or otherwise ensure that this will never occur.

## AUTHOR

Chris Gill           cdgill@cs.wustl.edu

Based on Command Pattern implementations originally done by

Carlos O'Ryan        coryan@cs.wustl.edu  and Douglas C. Schmidt   schmidt@cs.wustl.edu and Sergio Flores-Gaitan sergio@cs.wustl.edu

and on STL-style functor implementations originally done by

Irfan Pyarali  irfan@cs.wustl.edu

## LIBRARY

ace