Debugging With C++ Templates

dbx supports C++ templates. You can load programs containing class and function templates into dbx and invoke any of the dbx commands on a template that you would use on a class or function, such as:

• Setting breakpoints at class or function template instantiations

• Printing a list of all class and function template instantiations

• Displaying the definitions of templates and instances

• Calling member template functions and function template instantiations

• Printing values of function template instantiations

• Displaying the source code for function template instantiations

Template Example

The following code example shows the class template Array and its instantiations and the function template square and its instantiations.

In the following example:

• Array is a class template

• square is a function template

• Array<int> is a class template instantiation (template class)

• Array<int>::getlength is a member function of a template class

• square(int, int*) and square(double, double*) are function template instantiations (template functions)

  ---

   1		template<class C> void square(C num, C *result
   2		{
   3	 		*result = num * num;
   4		}
   5	
   6		template<class T> class Array
   7		{
   8		public:
   9	  		int getlength(void)
  10	 		{ 
  11	    			return length;
  12	  		}
  13	
  14	  		T & operator[](int i)
  15	  		{
  16	    			return array[i];
  17	 		}
  18	
  19	  		Array(int l)
  20	  		{ 
  21	    			length = l; 
  22	    			array = new T[length];
  23	  		} 
  24	  
  25	 	 	~Array(void)
  26	  		{ 
  27	   	 		delete [] array;
  28	  		} 
  29	
  30		private:  
  31	  		int length; 
  32	  		T *array; 
  33		}; 
  34	 
  

  ---

  ---

  35		int main(void)
  36		{ 
  37	  		int i, j = 3; 
  38	 		square(j, &i); 
  39	 
  40	 		double d, e = 4.1; 
  41	  		square(e, &d); 
  42	   
  43	  		Array<int> iarray(5); 
  44	  		for (i = 0; i < iarray.getlength(); ++i)
  45	  		{ 
  46	   			iarray[i] = i; 
  47	 		} 
  48	  
  49	  		Array<double> darray(5);     
  50	  		for (i = 0; i < iarray.getlength(); ++i)
  51	 		{  
  52	    			iarray[i] = i * 2.1;
  53	  		} 
  54	   
  55	  		return 0; 
  56		}
  

  ---