Convert from predefined type to own CMyString

Question

Let's say I have a function called dummy defined in the following way:

void dummy(CMyString& mystr)
{
   mystr.print(); //show
}

CMyString would be my own implementation of strings using an array of chars.

int main()
{
   dummy("This is a test!");
   return 0;
}

I'd like the following program to print out : "This is a test!". Is this possible?

score 3 · Accepted Answer · edited Nov 06 '12 at 09:53

3

Yes it is, you just need to provide a non-explicit conversion constructor to CMyString:

class CMyString
{
public:
    CMyString(const char* x); 
    //.....
};

and, of course, implement the CMyString::print method. After this you need to change the parameter to

void dummy(const CMyString& mystr)

(and mark the print method as const) because you can't bind a temp to a non-const reference.

edited Nov 06 '12 at 09:53

Chowlett

answered Nov 06 '12 at 09:39

Luchian Grigore

the dummy function accepts input by reference, does the compiler pre instantiate a temporary CMyString object before passing the reference to the dummy function? – fire xzanderr Nov 06 '12 at 09:48
@firexzanderr I was just adding that. You need a const reference. – Luchian Grigore Nov 06 '12 at 09:49
Very good. Where could I find such info & more advanced on c++ classes for further reading? Multumesc. – fire xzanderr Nov 06 '12 at 10:47
@firexzanderr vezi http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list – Luchian Grigore Nov 06 '12 at 11:35

score 1 · Answer 2 · answered Nov 06 '12 at 09:40

1

Certainly. You just need to define a constructor for CMyString that takes an array of chars or a pointer to char as its sole argument. Like so:

class CMyString
{
public:
  CMyString(const char* str)
  {
    // Initialise CMyString with str
  }
};

answered Nov 06 '12 at 09:40

Chowlett

2 Answers2