dmd samples are legacy

[dlangBugzillaToGithub]

SHOO (@shoo) reported this on 2013-12-07T10:28:53Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=11710

Description

Because update is delayed for the accompanying sample of dmd, it shows very old-fashioned codes.
Today, I saw the example that held a bad impression for the whole D language to see this sample codes. It is to be very regretted that D language itself was judged from such a trivial things.
To avoid this, it is necessary to discard samples or to make better codes.
I hope the sample codes appropriate to say "That's the code of the D Programming Language!"

Specifically, I think that improvement is necessary in the following points:

* Don't depend on the module of the C language as much as possible.
* Signature of the main function; `void main(string[] args)`
* To use foreach for loops.
* Don't use deprecated modules.
* Use inferences / Use enum for constant numbers / Use scope guard statements / etc.