How to declare immutable struct outside of try catch and reference it later

[Fra Mecca]

I have this code:
     Configuration conf = void ;
     try {
         conf = parse_config("config.sdl");
     } catch (Exception e) {
         std.stdio.stderr.writeln("Error reading configuration 
file: ", e.msg);
         exit(1);
     }

// other code
function(value, conf);
// end

I get:
source/app.d(18,3): Error: cannot modify struct conf 
Configuration with immutable members

Is there a way to declare conf outside of the try catch block and 
use it later?
I thought void explicitly avoid inizialization.