Code shared from run.dlang.io.

main.d

import std;
void main()
{
    string point;
    void * pointeraddress = &point;
    string[void *] associative;
    
    associative[pointeraddress] = "someinformation";
        
    writeln("Hello D ", pointeraddress);
	writeln("Hello D ", associative[pointeraddress]);
}