dsimcha Wrote: > == Quote from Bartosz Milewski (bartosz-nos...@relisoft.com)'s article > > > int[] a = [0]; > > > auto b = a; > > > a ~= 1; > > > b ~= 2; > > > What is a[1]? > > > > > > Is this considered "stomping" and requiring a re-allocation? > > Can this question be answered without the recourse to implementation, and > > the > MRU cache in particular? > > I thought about an abstract definition of "stomping".Something like that: > > The > expanded part of the array is never implicitly shared with any other array. > But > I'm not sure about this case: > > int[] a = [1, 2, 3]; > > int[] b = a[0..1]; > > b ~= 4; > > what is a[1]? > > By my definition, this would be considered stomping, but I couldn't find > > this > example in TDPL. > > a[1] == 2. The MRU cache stores both the pointer and the length. When you > attempt to append to b, the MRU is searched. No array that starts at b.ptr > and > has length b.length is found. b is reallocated.
Consider there is also c: int[] c = b[0..1]; According to the above definition, after b~=4 'b' would be relocated and b[0] would be disjoint from c[0]. Now consider that a's definition is changed to just [ 1 ]. If I understand this correctly, then b.ptr and b.length would match the original array, and in this case b ~= 4 operation might not relocate b, and b[0] and c[0] would refer to the same element. A change in 'a' would be defining the relation between b and c. Ali
