DouKaku?

module doukaku;
private import std.regexp;
private import std.stdio;

char[] remove_comment(char[] str) {
    return sub(str, r"/\*(.+?)(\*/|$)", "", "g");
}

int main () {
    writefln(remove_comment("AAA"));
    writefln(remove_comment("AAA/*BBB*/"));
    writefln(remove_comment("AAA/*BBB"));
    writefln(remove_comment("AAA/*BBB*/CCC"));
    writefln(remove_comment("AAA/*BBB/*CCC*/DDD*/EEE"));
    writefln(remove_comment("AAA/a//*BB*B**/CCC"));
    return 0;
}