Obtaining type and value of a variable named in another variable

[Paul Backus]

On Sunday, 17 October 2021 at 02:42:54 UTC, Tejas wrote:
>
> Doesn't solve the compile-time only problem though :(
> The only solution I can think of is something with `variant`s, 
> but it'll be messy.

Well, the fundamental issue is that in a language like D that 
compiles to machine code, variable names only exist at compile 
time. At runtime, the only thing you have is memory addresses 
(pointers).

If you want to look something up by name at runtime, you will 
have to use a data structure like an associative array:

```d
void main()
{
     int[string] vars = ["fooVar": 4];
     string strVar = "fooVar";

     writeln(typeof(vars[strVar]).stringof);
     writeln(vars[strVar]);
}
```

Of course, in this example, the associative array can only store 
`int`s. If you want to store multiple types of data, you will 
need to use a data type that supports runtime polymorphism, like 
a class, a sum type, or a variant.