std::for_each, calling member function with reference parameter
-
10-07-2019 - |
Question
I have a container of pointers which I want to iterate over, calling a member function which has a parameter that is a reference. How do I do this with STL?
My current solution is to use boost::bind, and boost::ref for the parameter.
// Given:
// void Renderable::render(Graphics& g)
//
// There is a reference, g, in scope with the call to std::for_each
//
std::for_each(
sprites.begin(),
sprites.end(),
boost::bind(&Renderable::render, boost::ref(g), _1)
);
A related question (from which I derived my current solution from) is boost::bind with functions that have parameters that are references. This specifically asks how to do this with boost. I am asking how it would be done without boost.
Edit: There is a way to do this same thing without using any boost
. By using std::bind
and friends the same code can be written and compiled in a C++11-compatible compiler like this:
std::for_each(
sprites.begin(),
sprites.end(),
std::bind(&Renderable::render, std::placeholders::_1, std::ref(g))
);
Solution
This is a problem with the design of <functional>
. You either have to use boost::bind or tr1::bind.
OTHER TIPS
Check out How to use std::foreach with parameters/modification. The question shows how to do it using a for loop. The accepted answer gives an example of how to achieve this with the for_each algorithm.