bison, union and struct YYSTYPE, c++

Dear all,


I'm using bison to generate a scanner and g++ to compile it.
Unfortunately, I found that I can't insert classes with a constructor
into a union (YYSTYPE), and I found it quite annoyng. My workaround
is no to use the %union declaration, but to explicitly define YYSTYPE
as a struct, i.e.


%{
#include "MyClass.h"


....


typedef struct {
MyClass c1;
MySecondClass c2;
double number;
} YYSTYPE;


extern YYSTYPE yylval;


%}


%token <c1> CLASS1_TOK
%token <c2> CLASS2_TOK
%token <number> NUMBER_TOK
.....


%type <c1> c1exp


%%


.....


c1exp: CLASS1_TOK { $$ = $1; }
| ......


%%




It seems to work, but is this a correct solution to the problem?
Am I making some silly errors?


MyClass and MySecondClass are not big, and have defined
a copy operator.




Thanks in advance for your answers and your suggestions,


Marco Morandini

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