Re: Bison C++ mid-rule value lost with variants

[Hans Åberg]

> On 29 Jun 2017, at 15:55, Piotr Marcińczyk <address@hidden> wrote:
> 
> I supposedly found a bug in lalr1.cc skeleton with variant semantic type.

You might check if std::variant, of C++17, can be used instead. Cf.
  http://en.cppreference.com/w/cpp/utility/variant

> When using mid-rule action { $<type>$ = value; } to return a value that
> will be used in further semantic actions, it appears that the value on
> stack becomes zero. Tested with Bison version 3.0.4.

This happens also if moved out to a separate rule, perhaps overwritten by the 
token semantic value. So it does not look safe for use.