program Project3;

{$APPTYPE CONSOLE}
{$R *.res}
uses
  System.SysUtils;

var
  Str: string = 'Test';

begin
  try
    Str := Str + ' Hello';
    Writeln(Str);
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
  Readln;

end.

procedure _UStrSetLength(var Str: UnicodeString; NewLength: Integer);
var
  P: PStrRec;
  Temp: Pointer;
  CopyCount: Integer;
begin
  if NewLength <= 0 then
    _UStrClr(Str)
  else
  begin
    if Pointer(Str) <> nil then
    begin
      if __StringRefCnt(Str) = 1 then
      begin
        P := Pointer(PByte(Str) - Sizeof(StrRec));
        if Cardinal(NewLength) >= Cardinal(- SizeOf(StrRec) - SizeOf(WideChar)) div 2 then
          _IntOver;
        _ReallocMem(Pointer(P), (NewLength + 1) * SizeOf(WideChar) + SizeOf(StrRec));
        P.length := NewLength;
        Pointer(Str) := Pointer(PByte(P) + SizeOf(StrRec));
        PWideChar(Str)[NewLength] := #0;
        Exit;
      end;
    end;
    Temp := _NewUnicodeString(NewLength);
    if Pointer(Str) <> nil then
    begin
      CopyCount := __StringLength(Str);
      if CopyCount > NewLength then
        CopyCount := NewLength;
      Move(PWideChar(Str)^, PWideChar(Temp)^, CopyCount * SizeOf(WideChar));
      _UStrClr(Str);
    end;
    Pointer(Str) := Temp;
  end;
end;

function _NewUnicodeString(CharLength: Integer): Pointer;
var
  P: PStrRec;
begin
  Result := nil;
  if CharLength > 0 then
  begin
    // Allocate a memory with record and extra wide-null terminator.
    if CharLength >= (MaxInt - SizeOf(StrRec)) div SizeOf(WideChar) then _IntOver;
    GetMem(P, SizeOf(StrRec) + (CharLength + 1) * SizeOf(WideChar));
    Result := Pointer(PByte(P) + SizeOf(StrRec));
    P.length := CharLength;
    P.refCnt := 1;
    P.elemSize := SizeOf(WideChar);
    P.codePage := Word(DefaultUnicodeCodePage);
    PWideChar(Result)[CharLength] := #0;
  end;
end;

 _PAnsiChr(Str)[NewLength] := #0;

procedure _LStrSetLength(var Str: _AnsiStr; NewLength: Integer; CodePage: Word);
var
  P: PStrRec;
  Temp: Pointer;
  CopyCount: Integer;
begin
  if newLength <= 0 then
  begin
    _LStrClr(Str);
    Exit;
  end
  else
  begin
    if Pointer(Str) <> nil then
    begin
      if __StringRefCnt(Str) = 1 then
      begin
        P := Pointer(PByte(Str) - Sizeof(StrRec));
        _ReallocMem(Pointer(P), NewLength + 1 + SizeOf(StrRec));
        P.length := NewLength;
        Pointer(Str) := Pointer(PByte(P) + SizeOf(StrRec));
        _PAnsiChr(Str)[NewLength] := #0;
        Exit;
      end;
    end;
    Temp := _NewAnsiString(NewLength, CodePage);
    if Pointer(Str) = nil then
    begin
      Pointer(Str) := Temp;
      Exit;
    end;
    CopyCount := __StringLength(Str);
    if CopyCount > NewLength then
      CopyCount := NewLength;
    Move(_PAnsiChr(str)^, _PAnsiChr(Temp)^, CopyCount);
    _LStrClr(Str);
    Pointer(Str) := Temp;
  end;
end;

program Project3;

{$APPTYPE CONSOLE}
{$R *.res}
uses
  System.SysUtils;

var
  Str: string = 'Test';
  NStr: PWideChar;

begin
  try
    Str := Str + ' Hello';
    NStr := PWideChar(Str);
    Writeln(NStr);
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
  Readln;

end.

  IMalloc = interface(IUnknown)
    ['{00000002-0000-0000-C000-000000000046}']
    function Alloc(cb: Longint): Pointer; stdcall;
    function Realloc(pv: Pointer; cb: Longint): Pointer; stdcall;
    procedure Free(pv: Pointer); stdcall;
    function GetSize(pv: Pointer): Longint; stdcall;
    function DidAlloc(pv: Pointer): Integer; stdcall;
    procedure HeapMinimize; stdcall;
  end;