get a struct member pointer

[Christopher Wright]

Jeffry Nox wrote:
> struct A {
> 	uint id=0;
> 	char[] name;
> }
> 
> struct B {
> 	uint id=0;
> 	char[] title;
> }
> 
> void lookup(T)(T[] s, ***)
> {
>   char[] txt = s[0].***;
> }
> 
> as illustrated above, how can i get struct object property info as in *** so i can manipulate it inside the function lookup above? in function lookup, i didnt know what is the variable name for the char[], so *** pass in the 2nd parameter, question is how to pass that member info or pointer so that it works on different struct declarations?
> 

Use tupleof. You need to specify a compile-time constant value as the 
index to tupleof, but looping also works:


import tango.io.Stdout;

struct S
{
     int i;
     char[] b;
}

void getItem (S s, int index)
{
     foreach (i, n; s.tupleof)
     {
         Stdout.formatln("{} {}", i, typeid(typeof(s.tupleof[i])));
         if (i == index)
         {
             auto value = s.tupleof[i];
             Stdout.formatln("Value is `{}`", value);
         }
     }
}

void main (char[][] args)
{
     S s;
     getItem(s, 0);
     getItem(s, 1);
}