Re: [Boost-users] [phoenix] Basic recursive function.

13 Apr 2011


      At Wed, 13 Apr 2011 16:10:12 +0100,
Robert Jones wrote:
...
I'm a newbie to Phoenix, just exploring, but I guess my intent in this code
is
obvious. Can anyone tell me what I'm doing wrong?
Thx
- Rob.
#include <iostream>
#include 
#include 
#include 
#include 
using namespace boost::phoenix;
using namespace boost::phoenix::arg_names;
using namespace std;
int main()
{
    boost::function factorial;
    factorial = if_else( _1 == 0, 1, _1 * factorial( _1 - 1 ) );
I think you'd better find a way to store factorial by reference in the
phoenix expression, because the value at the time of building is
empty.  Totally guessing:


        factorial = if_else( _1 == 0, 1, _1 * ref(factorial)( _1 - 1 ) );


-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com