I’d like to know if there is a solution to the problem of indexing into records
using [] properties.
In the example below I have an array of records (a dynamic array for the
example) and I’d like to use the [] property to index into the values. The
problem is because the array holds records I need to return a pointer to the
record so I can access the fields. In the end the only problem is I need to
dereference the pointer using ^.
Are there any solutions we could propose to this? Some ideas:
1) I looks like we could have a “var” modifier for function results but that
concept has only ever existed in function params (like & in C++).
function GetValue(i: integer): TVec2; var;
2) Maybe a modifier added to GetValue which tells the compiler to call the
function (and result) like a pointer when the indexer is used?
====================================
type
TVec2 = record
x, y: integer;
end;
TVec2Ptr = ^TVec2;
TVec2Array = array of TVec2;
type
TVecArray = class
values: TVec2Array;
function GetValue(i: integer): TVec2Ptr;
procedure Resize(newLength: integer);
property Indexer[i: integer]: TVec2Ptr read GetValue; default;
end;
function TVecArray.GetValue(i: integer): TVec2Ptr;
begin
result := @values[i];
end;
procedure TVecArray.Resize(newLength: integer);
begin
SetLength(values, newLength);
end;
var
arr: TVecArray;
begin
arr := TVecArray.Create;
arr.Resize(1);
arr[0]^.x := 100;
arr[0]^.y := 100;
end.
Regards,
Ryan Joseph
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