Does bind() have any advantage (other than compatibility) over C++11 lambdas?

Question

I'm thinking about migrating my code toward using C++11-style lambdas instead of having binds everywhere. But I'm not sure if it's a good idea or not.

Does using e.g. boost::lambda (or boost::phoenix) have any practical advantage over C++11-style lambdas?

Is it a good idea to move over to lambdas? Should I migrate my code or not?

Answer 1

The main advantage would be polymorphic functors. Currently, C++11 lambdas are monomorphic, i.e., they only take single argument type, whereas bind() allows you to create functors that accept any argumen type as long as the bound functor is callable with it.

#include <functional>

struct X{
  template<class T, class U>
  void operator()(T, U) const{}
};

int main(){
  X x;
  auto l_with_5 = [x](int v){ return x(v, 5); };
  auto b_with_5 = std::bind(x, std::placeholders::_1, 5);
  l(4);
  b("hi"); // can't do that with C++11 lambdas
}