How to use "read_bool"?

[simendsjo]

On Fri, 03 Aug 2012 08:05:46 +0200, Ali Çehreli <acehreli at yahoo.com> wrote:

> On 08/02/2012 09:17 PM, Zeh wrote:
>  > Hi, i am just a newbie trying learn D. But, i get having some trouble
>  > with "read_bool". More specifically on program of this lesson:
>
> As Timon said, read_bool() is a separate function on the same page, a  
> little after main():
>
> bool read_bool(string message)
> {
>      // Print the message
>      writef(message ~ "(false or true) ");
>
>      // Read the line as a string
>      string input;
>      while (input.length == 0) {
>          input = chomp(readln());
>      }
>
>      // Produce a 'bool' value from that string
>      bool result = to!bool(input);
>
>      // Return the result to the caller
>      return result;
> }
>
> Unlike Timon's function, you must enter either "false" or "true" with  
> the one above.
>
> Ali
>

What tutorials is this? Here's another version:

import std.stdio, std.string, std.conv;

bool read_bool(in string message) { // in as we don't escape or modify the  
input
     while(true) { // loop until we get true/false
         write(message, " (false or true): "); // avoid concat allocation
         string input;
         do { // no need to check input on entering
             input = readln().chomp(); // UFCS
         } while(!input); // no need to check length

         try
             return input.to!bool;
         catch {} // don't care if it's not true/false. Keep nagging
     }
}

void main() {
     auto input = read_bool("Do it?");
     writeln(input ? "Hell yeah, do it!" : "No way!");
}