flatten(x)

Returns a "flattened" representation of x as a vector of real numbers, and a function unflatten that takes a vector of reals of the same length and returns an object of the same type as x. unflatten is the inverse of flatten, so

julia> x = (randn(5), 5.0, (a=5.0, b=randn(2, 3)));
julia> v, unflatten = flatten(x);
julia> x == unflatten(v)
true