how to transform decial point "3.15" to "3,15" comma?

[AsmMan via Digitalmars-d-learn]

On Monday, 15 September 2014 at 23:17:51 UTC, AsmMan wrote:
> On Monday, 15 September 2014 at 22:45:50 UTC, Cassio Butrico 
> wrote:
>> how to transform decial point "3.15" to "3,15" comma?
>>
>> Hello everyone, I am making a registry of real amounts,
>> and need trasformar fractional numbers,
>> so print coretamente.
>>
>> there is some routine that do this?
>
> Is the , (comma) the system decimal separator? if so, you can 
> use C intero and include locale.h header (in D, the respective 
> module) call setlocale(LC_NUMERIC, "") function and then 
> printf("%g", 3.5) will output (if decimal separator is the 
> comma): 3,5
>
> I haven't tested it in D but I think D's writefln() will behave 
> exactly same as C's printf().. but it didn't you're free to 
> call C's printf()

The code is the following:

import std.stdio;
import std.c.locale;

void main()
{
	setlocale(LC_NUMERIC, "");
	writeln(3.5); // 3,5
}

You can change/see current decimal separator using (assuming
Windows) http://www.softwareok.com/?seite=faq-Win-7&faq=78