Improvement: to enable new switch for D-lang (DMD/LDC)

Feedback & Bugs
#1

Error: shortened method not enabled, compile with compiler switch -preview=shortenedMethods

for:
char and(char a, char b) => a == ‘-’ and b == ‘-’ && ? ‘-’ : ‘';
instead:
char and(char a, char b) { return a == ‘-’ and b == ‘-’ && ? ‘-’ : '’; }