digitalmars.D.learn - Error: array operation d1[] + d2[] without assignment not implemented
- deed (19/19) Sep 13 2014 struct Vector (T)
- Ilya Yaroshenko (13/32) Sep 13 2014 Hi!
- deed (7/19) Sep 13 2014 Thanks for your suggestion. It's not as attractive though, it
- Ilya Yaroshenko (2/2) Sep 13 2014 Operations like "ar1[] op= ar2[] op ar3[]" is only for arrays.
struct Vector (T) { T[]arr; void opSliceAssign (T[] a) { arr[] = a[]; } } unittest { auto v = Vector!double([1, 2]); double[] d1 = [11, 12]; double[] d2 = [21, 22]; double[] d3 = new double[](2); d3[] = d1[] + d2[]; assert (d3 == [11.+21., 12.+22.]); assert (is(typeof(d1[] + d2[]) == double[])); v[] = d1[] // Fine v[] = d1[] + d2[]; // Error: array operation d1[] + d2[] without assignment not implemented } How can opSliceAssign be defined to make this work?
Sep 13 2014
On Saturday, 13 September 2014 at 14:18:57 UTC, deed wrote:struct Vector (T) { T[]arr; void opSliceAssign (T[] a) { arr[] = a[]; } } unittest { auto v = Vector!double([1, 2]); double[] d1 = [11, 12]; double[] d2 = [21, 22]; double[] d3 = new double[](2); d3[] = d1[] + d2[]; assert (d3 == [11.+21., 12.+22.]); assert (is(typeof(d1[] + d2[]) == double[])); v[] = d1[] // Fine v[] = d1[] + d2[]; // Error: array operation d1[] + d2[] without assignment not implemented } How can opSliceAssign be defined to make this work?Hi! struct Vector (T) { T[]arr; T[] opSlice() { return arr; } } Vector!double v; double[] d; v[][] = d[] + d[]; //first [] call opSlise, second [] for array syntax Best Regards, Ilya
Sep 13 2014
Hi! struct Vector (T) { T[]arr; T[] opSlice() { return arr; } } Vector!double v; double[] d; v[][] = d[] + d[]; //first [] call opSlise, second [] for array syntax Best Regards, IlyaThanks for your suggestion. It's not as attractive though, it would be the same as v.arr[] = ..., exposing the naked array. The syntax also becomes a bit confusing. With alias this it works, but functionality is lost. See http://dpaste.dzfl.pl/35081c1f1745 It feels not consistent, so I guess that's the reason for the "not implemented" message.
Sep 13 2014
Operations like "ar1[] op= ar2[] op ar3[]" is only for arrays. There is no operator overloading for this staff.
Sep 13 2014