can be an element that is implicitly convertible to T, an input range of such elements, or another Array
the newly created array
Complexity: O(n + m), where m is the number of elements in rhs.
import std.algorithm.comparison : equal; auto a = Array!int(1); auto a2 = a ~ 2; assert(equal(a2, [1, 2])); a.front = 0; assert(equal(a2, [1, 2]));
Create a new array that results from the concatenation of this array with rhs.