C++ istream / ostream equivalent ?

[Matthias Pleh]

>
> Thank you for your reply and yes that works :)
>
> Now i m facing with the following problem, what is the trick for input stream ?
>
> ( something like
>
> std::istream&  operator>>(std::istream&  in,A&  a)
> {
>    //  A.someData<<  in;
>    return in;
> }
>
> in C++ )
>
> I m thinking of the situation when we want to load some data from a file.
>
> The toString() trick is okay for saving the object... but how to load it back (something like fromString(char[]) would do the job but it does not exist in Object) ?
>
> Anyway thank you, you solved half of my problem :)
>
>

Ther are many posibilities, depending on your further needs! Just have a 
look at the online dokumentation:
http://www.digitalmars.com/d/2.0/phobos/phobos.html

But my first try would be such ..
(note: I've leaved out error-handling ...)

module test;

import std.stdio;
import std.file;

class A
{
     void writeToFile()  { std.file.write("sample.txt",someData);   }
     void readFromFile() { someData=cast(string)read("sample.txt"); }
     void clear()        { someData="n/A\n"; }
     string toString()   { return someData;  }
private:
     string someData="Just some data.
With anohter line of date.
Even more data.!";	
}

int main(string[] args)
{
	A a=new A;
	a.writeToFile();
	a.clear();
	writeln(a);
	a.readFromFile();
	writeln(a);
	return 0;
}