Could I safety replace pointer with call by reference?
lazarus / 62-General

----------------------------------------------------------------------
jiaxing2 · 2020-05-14 06:01

It's in my C library binding. In C they use pointer. I want to know if
I could substitue pointer with call by reference

----------------------------------------------------------------------
PascalDragon · 2020-05-14 07:39

In general you can. The only case where you shouldn't is if the
pointer is allowed to be Nil, cause a var, out or constref parameter
can not be a reference to nothing.

----------------------------------------------------------------------
LemonParty · 2020-05-14 08:19

Quote from: PascalDragon on May 14, 2020, 09:39:48 amThe only case
where you shouldn't is if the pointer is allowed to be Nil, cause a
var, out or constref parameter can not be a reference to nothing.
No, you can.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
F(var b: Integer): Integer;begin if @b = nil then 
Writeln('nil');end; begin F(PInteger(nil)^);end.

----------------------------------------------------------------------
PascalDragon · 2020-05-14 08:32

Quote from: LemonParty on May 14, 2020, 10:19:00 amQuote from:
PascalDragon on May 14, 2020, 09:39:48 amThe only case where you
shouldn't is if the pointer is allowed to be Nil, cause a var, out or
constref parameter can not be a reference to nothing.
No, you can.

Yes, but this is not obvious to most. Also you need to have a pointer
type to the parameter type declared.