On Thursday, 5 October 2023 at 16:40:49 UTC, Gaurav Negi wrote:
Well, in the D programming language, both opIndex and opSlice
are two different operators used to access elements of a custom
type.
Yeah, D is on its way to becoming a near-perfect programming
language...
```d
enum initialSituation = [1, 2, 3];
import std.stdio;
void main()
{
auto s = S(initialSituation);
s[] = 1;
s[1] = 2;
s[2] += 2;
assert(s.arr == initialSituation);
auto d = s *= 2;
assert(d == S([2, 4, 6]));
}
/* Prints:
[1, 1, 1]: onlineapp.S.opSliceAssign
[1, 2, 1]: onlineapp.S.opIndexAssign
[1, 2, 1]: onlineapp.S.opIndex
[2, 4, 6]: onlineapp.S.opOpAssign!"*".opOpAssign
*/
struct S
{
int[] arr;
auto opSliceAssign (int value)
{
scope(exit)
{
writefln("%s: %s", arr, __FUNCTION__);
}
return arr[] = value;
}
auto opIndexAssign(int value, int index)
{
scope(exit)
{
writefln("%s: %s", arr, __FUNCTION__);
}
arr[index] = value;
}
ref opIndex(size_t index)
{
scope(exit)
{
writefln("%s: %s", arr, __FUNCTION__);
}
return arr[index];
}
ref opOpAssign(string op)(int value)
{
scope(exit)
{
writefln("%s: %s", arr, __FUNCTION__);
}
mixin("arr[] " ~ op ~ "=value;");
return this;
}
}
```
SDB@79
