> On 18 Aug 2016, at 18:07, Min Wang <mingew...@gmail.com> wrote:
> (1) when ListExp was returned up to PROG (e.g: PROG($1)), does it use copy > constructor? or > use move constructor if it existed? A part from translation of the $-variables, the action code is copied verbatim to the C++ parser. So do not think move constructors are invoked, since that happens in special syntactic context where it is known that a variable will perish. > (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? Don’t use that, because in some cases there may be an implicit $$ = $1, which might make it obsolete. Instead use a reference count or a GC, like the Hans Boehm one: http://www.hboehm.info/gc/ _______________________________________________ help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
