Namespace Types

Namespaces groups ACDK classes and interfaces into a logical unit.

Content of this chapter:

   Using types from other namespaces
     using namespace
     using declaration
   Creating own namespaces

Using types from other namespaces

Full qualified identifier To address objects from other namespace you can use the full qualified identifiers:


#include <acdk/io/File.h>

bool foo()
{
  ::acdk::lang::RString str = "./temp.file";
  ::acdk::io::RFile file = new ::acdk::io::File(str);
  return file->exists();
}

using namespace

You can import the scope of another namespace with the C++ using:


#include <acdk/io/File.h>
using namespace ::acdk::lang;
using namespace ::acdk::io;

bool foo()
{
  RString str = "./temp.file";
  RFile file = new File(str);
  return file->exists();
}

Unfortunatelly in many C++ compiler namespaces are buggy implemented, and it is better not import the scope complete namespaces.

using declaration

You can import single classes with C++ using declaration:


#include <acdk/io/File.h>

using ::acdk::lang::RString;
using ::acdk::io::File;
using ::acdk::io::RFile;

bool foo()
{
  RString str = "./temp.file";
  RFile file = new File(str);
  return file->exists();
}

To make life a little bit more easy ACDK provides an own using:


#include <acdk/io/File.h>

// using now String, RString, StringArray and RStringArray
USING_CLASS(::acdk::lang::, String);

// using now File, RFile, FileArray, RFileArray
USING_CLASS(::acdk::io::, File);

bool foo()
{
  RString str = "./temp.file";
  RFile file = new File(str);
  return file->exists();
}

Writing your own ACDK classes you should group it into a namespace following the java standard pattern:

Your app name: myapp.
Your company url: artefakur.com.
the namespace: com::artefaktur::myapp
Sample Header:


// this is myapp/src/com/artefaktur/myapp/MyClass.h
#ifndef com_artefaktur_myapp_MyClass_h
#define com_artefaktur_myapp_MyClass_h
namespace com {
namespace artefaktur {
namespace myapp {

class MyClass
: extends acdk::lang::Object
{
  // ...
};
} // namespace myapp 
} // namespace artefaktur 
} // namespace com 
#endif //com_artefaktur_myapp_MyClass_h