Question

in c++ please explain with answer

6. Given the following template function definition, which of the following is not a valid
invocation of the function?

template <class T>	a.	swap(s1,s2);
void swap(T& left, T& right)	b.	swap(int1, int2);
{	c.	swap(ch1, ch2);
//implementation	d.	swap(int1, ch2);
}
int int1, int2;
float flt1, flt2;
char ch1, ch2;
string s1, s2;

7. Why can you not use the swap template function to swap two complete arrays?

template <class T>

void swap(T& left, T& right)

{

20. tmp=left;

left=right;

right=tmp;

}

1. You can not pass an array name to a function

2. The swap function does not return anything
3. the = operator does not work for an array
4. tmp should be an integer

8. In the following function template, what must be true in order to use the function with a
given data type?

template <class T>	a.	the data type must be a pre-defined data type
int smallest( T array[], int size)	b. the data type must have a < operator defined for
{		it
int small=0, i;	c. the data type must be numeric
for(i=0;i<size;i++)	d. the data type must be character based
{
if(array[i] < array[small])
small=i;
}
return small;
}

9. Given a class template, how many different times can you instantiate the class?
10. 1. 0
11. 2. 1
    3. 1 for each different data type
12. 4. as many as you need, but only one data type
    5. as many as you need, of any data types
13. 10. Which library must be included to handle bad_alloc error?
14. 1. #include <iostream>
15. 2. #include <cstdlib>
16. 3. #include <new>
17. 4. #include <assert>

Answer 1

6. The answer is D. Since, you can swap two values of same type as in A, B, C like integer to integer, character to character but in D we are trying to swap values of different types therefore it is incorrect.

7. Answer is C since you cannot directly transfer or swap array elements using =. You must get individual element and then swap.

8. The data type can be of numeric or character but it should be predefined. Therefore, option A is correct.

9. It is E.
10. It is C. It is defined in new header file.