Basic Data Types

The CORBA mappings for some primitive datatypes are given in the following table.

IDL Data Type	C++ Mapping	Data Size
short	CORBA::Short	size >=16bits
unsigned short	CORBA::UShort	size >= 16 bits
long	CORBA::Long	size>=32 bits
unsigned long	CORBA::ULong	size>=32 bits
char	CORBA::Char	size>=8
boolean	CORBA::Boolean	No Size specified
octet	CORBA::Octet	size>=8
float	CORBA::Float	size>=32 bits
double	CORBA::Double	size>=64bits

As all of the above data types follow a similar pattern, the table below demonstrates the long IDL data type. After this table, there are four examples of using the long as an in, out, inout, and return values for a some method.

Data Type(IDL)	in	out	inout	return
long	CORBA::Long arg	CORBA::Long &arg	CORBA::Long &arg	CORBA::Long

The first example is of an interface IData with a single operation TheData that takes an in argument of an long. The mappings for writing both the server and client are given.

 // Example #1 :CORBA IDL  - in argument of simple data types
interface IData
	{
	void TheData(in long data);
	};

	// Servant Code
	class MyHelloServant: public virtual POA_IData
		{
		public:
		void TheData(const CORBA::Long data);
		};

	/////////////////////////////////////////////////
	void MyHelloServant::TheData(const CORBA::Long data)
		{
		cout << "Client sent:"<<data<<endl;
		}

  
	// Client Code 
		{   IData_var obj;
		/* .... Initialize obj code is here ....*/

		obj->TheData(1234);

		CORBA::Long x=123;

		obj->TheData(x);
		
		}

The Example #2 demonstrates an out long argument.

 // Example #2 :CORBA IDL
interface IData
	{
	void TheData(out long data);
	};

	// Servant Code
	class MyHelloServant: public virtual POA_IData
		{
		public:
		void TheData(CORBA::Long &data);
		};

	////////////////////////////////////////
	void MyHelloServant::TheData(CORBA::Long &data)
		{
		data = 1234;  // sending back 1234
		}

  
	// Client Code 
		{   IData_var obj;
		/* .... Initialize obj code is here ....*/

		CORBA::Long x;

		obj->TheData(x);
		cout << "Server sent:" << x <<endl;
		}

The Example #3 demonstrates an inout mapping of a long.

 // Example #3 :CORBA IDL
interface IData
	{
	void TheData(inout long data);
	};

	// Servant Code
	class MyHelloServant: public virtual POA_IData
		{
		public:
		void TheData(CORBA::Long &data);
		};

	/////////////////////////////////////////
	void MyHelloServant::TheData(CORBA::Long &data)
		{
		cout << "Client sent "<<data<<endl;
		data = 1234;  // sending back 1234
		}

  
	// Client Code 
		{   IData_var obj;
		/* .... Initialize obj code is here ....*/

		CORBA::Long x=1111;
		obj->TheData(x);
		cout << "Server sent:" << x <<endl;
		}

The Example #4 demonstrates a return value of a long.

 // Example #4 :CORBA IDL
interface IData
	{
	long TheData();
	};

	// Servant Code
	class MyHelloServant: public virtual POA_IData
		{
		public:
		CORBA::Long TheData(void);
		};

	////////////////////////////////////////
	CORBA::Long MyHelloServant::TheData(void)
		{
		return 1234;
		}

  
	// Client Code 
		{   IData_var obj;
		/* .... Initialize obj code is here ....*/

		CORBA::Long x;
		x=obj->TheData();
		cout << "Server sent:" << x <<endl;
		}

When you are using boolean in your IDL code, you have to be careful about what to use to initialize the variable. If you are using an ANSI-C++ compiler, boolean variables can have a value of true or false. But, for portability, use 1 for true and 0 for false. The Next Example #4 demonstrates a return value using a boolean type.

 // Example #5 :CORBA IDL
interface IData
	{
	boolean IsTrue();
	};

	// Servant Code
	class MyHelloServant: public virtual POA_IData
		{
		public:
		CORBA::Boolean TheData(void);
		};

	///////////////////////////////////////////////
	CORBA::Boolean MyHelloServant::TheData(void)
		{
		return 1;  // return TRUE
		}

  
	// Client Code 
		{   IData_var obj;
		/* .... Initialize obj code is here ....*/

		if(obj->IsTrue()) { cout<< "Function returned true"<<endl; }

		}

The Last Example(#6) of using data types is a complex function that takes several different data-types.

 // Example #6 :CORBA IDL
interface IData
	{
	boolean TheData(in long rangebegin,in long rangeend,out char ch,
			inout float age);
	};

	// Servant Code
	class MyHelloServant: public virtual POA_IData
		{
		public:
		CORBA::Boolean TheData(const CORBA::Long rangebegin,const CORBA::Long rangeend
			,CORBA::Char &ch,CORBA::Float age);
		};

	///////////////////////////////////////
	CORBA::Boolean MyHelloServant::TheData(const CORBA::Long rangebegin,const CORBA::Long rangeend
			,CORBA::Char &ch,CORBA::Float age)
		{
		ch='A';  cout<<age;  age = rangebegin+rangeend; return 0;
		}

  
	// Client Code 
		{   IData_var obj;
		/* .... Initialize obj code is here ....*/

		CORBA::Char ch;  CORBA::Float age=123;
		if ( obj->TheData(10,20,ch,age);
		cout << "Server sent:" << age << " "<< ch<<endl;
		}