Changing the class data underneath some reference

[David Colson]

On Thursday, 30 November 2017 at 00:40:51 UTC, David Colson wrote:
> Hello all!
>
> I'm getting settled into D and I came into a problem. A code 
> sample shows it best:
>
> class SomeType
> {
>     string text;
>     this(string input) {text = input;}
> }
>
>
> void main()
> {
>     SomeType foo = new SomeType("Hello");
>
>     SomeType bar = foo;
>
>     foo = new SomeType("World");
>
>     writeln(bar.text); // Prints hello
>     // I'd like it to print World
> }
>
> In the C++ world I could do this using pointers and changing 
> the data underneath a given pointer, but I can't use pointers 
> in D, so I'm not sure how I can get this behaviour?
>
> I'd be open to other ways of achieving the same affect in D, 
> using more D like methods.

I made an example demonstrating what I'd do in C++:

class SomeType
{
public:
     std::string text;
     SomeType(std::string input) {text = input;}
};


int main()
{
     SomeType foo = SomeType("Hello");

     SomeType* bar = &foo;

     foo = SomeType("World");

     std::cout << bar->text << "\n"; // Prints World
}