On Sunday, March 27, 2011 05:00:03 PM Lorenzo Caminiti wrote:
On Sun, Mar 27, 2011 at 9:38 AM, Thomas Heller <thom.heller@googlemail.com> wrote:
Correct version is:
#include <boost/phoenix/phoenix.hpp> // For Phoenix V2 uncomment this line, and comment the above: #include <boost/spirit/include/phoenix.hpp> #include <iostream> #include <vector> #include <algorithm>
int main() { double sum = 0.0; int factor = 10;
std::vector<double> v(3); v[0] = 1.0; v[1] = 2.0; v[2] = 3.0;
std::for_each(v.begin(), v.end(), ( boost::phoenix::ref(sum) += factor * boost::phoenix::arg_names::_1, std::cout << boost::phoenix::val("Summed: ") << boost::phoenix::ref(sum) << "\n" ));
std::cout << sum << std::endl; return 0;
Yes, this works :) Thanks a lot!
On a separate note, is there any way I can prevent the following `factor = 0` from compiling (e.g., making factor a const within the Phoenix function expression)?
#include <boost/spirit/include/phoenix.hpp> #include <iostream> #include <vector> #include <algorithm>
int main() { double sum = 0.0; int factor = 10;
std::vector<double> v(3); v[0] = 1.0; v[1] = 2.0; v[2] = 3.0;
std::for_each(v.begin(), v.end(), ( factor = 0, // <==== Can I prevent this with a compiler error?
No, because this is just plain old C++. assigning zero to a value ... there is nothing what phoenix can do here. The guy who wrote the code could have said: const int factor = 10; assignment would then be impossible^W not allowed.