FunVec3TLength1 Field

var underlyingList = new List<int> { 10, 11, 12 };
FunVec1<int> vec = new(underlyingList);
Assert(vec.Length1 == 3);

Func<int, bool> underlyingFun = i => i % 2 == 0;
vec = new(underlyingFun, length1: Some(4));
Assert(vec.Length1, 4);

Func<int, bool> underlyingFun = i => i % 2 == 0;
vec = new(underlyingFun); // omitted optional argument 'length1' defaults to None -> no limit
Assert(vec.Length1 == int.MaxValue);