alias Float = Variant!(float, double);
alias Int = Variant!(long, int);
alias Number = Variant!(Float.AllowedTypes, Int.AllowedTypes);

Number number = 3.0;
assert(number._is!Float);
auto fp = number.trustedGet!Float;
static assert(is(typeof(fp) == Float));
assert(fp == 3.0);

// type list overload
number = 12L;
assert(number._is!(int, long));
auto integer = number.trustedGet!(int, long);
static assert(is(typeof(integer) == Int));
assert(integer == 12L);