On Thu, 29 Jan 2004, Shawn Church wrote:
I may be missing something simple here but I have tried everything I can think of and cannot get the following to work (simplified from a project I am working on):
Lambda and format don't play well together, I noticed :( Here's a code that works however, with some explanation. Not pretty. Best, Jaakko #include <iostream> #include <iomanip> #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> #include <vector> #include <algorithm> #include <boost/format.hpp> class foo{ public: foo(const char* name): _name(name) {} const char* name() const {return _name.c_str();} private: std::string _name; }; using namespace boost::lambda; using namespace std; using namespace boost; int main() { std::vector<foo> Foos; Foos.push_back(foo("one")); Foos.push_back(foo("two")); for_each(Foos.begin(), Foos.end(), cout << bind(&foo::name, _1) << "|"); format f("%-10s|") ; for_each(Foos.begin(), Foos.end(), cout << ret<format&>(var(f) % bind(&foo::name, _1))); } // format defines operator% as a member, which takes precedence over // % defined by lambda. Therefore one must make the format object to // be a lambda functor. var does that. // Var, however, cannot take a temporary object (it holds a reference to // the wrapped object). That's why the variable f. // ret<format&> informs lambda about the return type of formats % operator.