Re: About %destructor is c++ mode

[Min Wang]

Hi

@hans. thanks!


Let's say I change to use c++ obj instead of pointer

e.g:
%type <PROG> PROG
%type <ListExp> ListExp

PROG : ListExp                      driver.store_ast( PROG($1) );
ListExp : Exp                       {  $$ = ListExp(); $$.push_back($1)); }
Exp : Exp "OR" Exp1                 {  $$ = Elor($1, $3)  ; }

using ListExp_PTR = std::unique_ptr<ListExp>;

class PROG
{
public:
  // should I use obj here?
  // ListExp listexp_;
   // or pointer?
  ListExp_PTR listexp_;

  ...
}

My some dummy questions are:

(1) when ListExp was returned up to PROG (e.g: PROG($1)), does it use copy
constructor? or
use move constructor if it existed?

(2) should I use object ( ListExp)  inside PROG class or  a
 std::unique_ptr inside the PROG to save some copy ? In the latter case,
how can I initial std::unique_ptr if the passed parameters if a obj?


thanks

min




On Thu, Aug 18, 2016 at 11:45 AM, Hans Åberg <address@hidden> wrote:

>
> > On 18 Aug 2016, at 16:03, Min Wang <address@hidden> wrote:
>
> > So I should use
> >
> > %type <PROG> PROG
> >
> > instead of
> >
> > %type <PROG*> PROG
>
> > Thus I do not need %destructor at all?
>
> If you write a proper C++ type T with T::~T destructor, then %destructor
> should not be used, nor explicit deallocation in the actions.
>
>


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