Mega Code Archive
How to make a procedurefunction with variable parameter count
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Title: How to make a procedure/function with variable parameter count
{ .... }
type
VA_FN = function(const par1, par2{, ...}: Pointer): Boolean;
cdecl varargs;
{ .... }
// varargs without "external" keyword
//
function fn(const par1, par2{, ...}: Pointer): Boolean; cdecl;
var
last_arg: Pointer absolute par2;
ptr_args: array[0..MAXLONG shr 2] of Pointer absolute last_arg;
dw_args: array[0..MAXLONG shr 2] of Cardinal absolute last_arg;
s_args: array[0..MAXLONG shr 2] of PChar absolute last_arg;
w_args: array[0..MAXLONG shr 2] of WideString absolute last_arg;
begin
// ptr_args[1] is first optional argument
Result := (ptr_args[1] {par3} = Pointer(1)) and
(dw_args[2] {par4} = 2) and
(string(ptr_args[3]) = 'CHAR') and
(w_args[4] = 'WCHAR');
end;
procedure test_fn;
begin
// VA_FN typecast
VA_FN(@fn)({par1}nil, {par2}nil, {par3}Pointer(1), {par4}2, {par5}'CHAR',
{par6}WideString('WCHAR'));
end;
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