From: "Albrecht Fritzsche" <albrecht.fritzsche@tiscali-dsl.de>

Here I want to extend simple callbacks so that these callbacks take an argument

void fun(int i) { std::cout << "Hi fun " << i << std::endl; } struct Foo { void bar(int i) { std::cout << "Hi bar " << i << std::endl; } }; template <class Value> struct CallFunction { CallFunction(const Value& v) : mValue(value) {} // defined outside void operator()(const boost::function<void, Value>& fun) { if (fun) fun(mValue); } const Value& mValue; };

int main() { std::vector< boost::function<void, int> > funs; Foo foo;

funs.push_back(&fun); funs.push_back(boost::bind(&Foo::bar, &foo, _1)); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ int value = 7; std::for_each(funs.begin(), funs.end(), CallFunction<int>(value));

return 0; }

Is this the right usage of the /_1/ here? This code runs (at least on my machine:-), but I'm quite unsure about this place holder. And since the online docu...

Yes, it looks correct. bind(&Foo::bar, &foo, _1) generates the following "function": void function(_1) { return ((&foo)->*(&Foo::bar))(_1); }

Ah, now I see - in the online doc there are some links missing. In the files section not only the bind_template.hpp link refers to that very file but also the arg.hpp and placeholders.hpp links and many more.

Fixed, thanks.