Redundant "g" flag for regex?

[Basile B.]

On Saturday, 23 June 2018 at 12:17:08 UTC, biocyberman wrote:
>
> I get the same output with or without "g" flag at line 6:
> https://run.dlang.io/is/9n7iz6
>
> So I don't understand when I have to use "g" flag.

My bet is that Regex results in D are lazy so "g" doesn't make 
sense in this context however I'm able to see an effect with 
"match":

match("12000 + 42100 = 54100", regex(r"(?<=\d)(?=(\d\d\d)+\b)", 
"")).writeln;
match("12000 + 42100 = 54100", regex(r"(?<=\d)(?=(\d\d\d)+\b)", 
"g")).writeln;

matchFirst would be like without "g"
matchAll would be like with "g"