How to call a member function on a parameter with std::for_each and boost::bind?

Question

I want to add a series of strings to a combo box using std::for_each. The objects are of type Category and I need to call GetName on them. How can I achieve this with boost::bind?

const std::vector<Category> &categories = /**/;
std::for_each(categories.begin(), categories.end(), boost::bind(&CComboBox::AddString, &comboBox, _1);

The current code fails as it's trying to call CComboBox::AddString(category). Which is obviously wrong. How can I call CComboBox::AddString(category.GetName()) using the current syntax?

Answer 1

std::for_each(categories.begin(), categories.end(), boost::bind(&CComboBox::AddString, &comboBox, boost::bind(&Category::GetName, _1)));

Answer 2

You can use lambdas, either Boost.Lambda or C++ lambdas (if your compiler supports them):

// C++ lambda
const std::vector<Category> &categories = /**/;
std::for_each(categories.begin(), categories.end(),
              [&comboBox](const Category &c) {comboBox.AddString(c.GetName());});

Answer 3

A possible way to achieve this would be using mem_fun and bind1st

Answer 4

I know you asked about using std::for_each, but in those cases I like using BOOST_FOREACH instead, it makes the code more readable (in my opinion) and easier to debug:

const std::vector<Category> &categories = /**/;
BOOST_FOREACH(const Category& category, categories)
    comboBox.AddString(category);