int main()
{
// store a free function
std::function<void(int)> f_display = print_num;
f_display(-9);
// store a lambda
std::function<void()> f_display_42 = []() { print_num(42); };
f_display_42();
// store the result of a call to std::bind
std::function<void()> f_display_31337 = std::bind(print_num, 31337);
f_display_31337();
// store a call to a member function
//std::function<void(const IFoo&, int)> f_add_display = &Foo::print_add;
Foo foo;
std::function<void(int)> f_add_display = std::bind(&Foo::print_add, &foo, std::placeholders::_1);
f_add_display(1);
f_add_display = nullptr;
if (f_add_display)
{
std::cout << "Should not write thuis." << '\n';
}
// store a call to a function object
std::function<void(int)> f_display_obj = PrintNum();
f_display_obj(18);
}
int main()
{
// store a free function
std::function<void(int)> f_display = print_num;
f_display(-9);
// store a lambda
std::function<void()> f_display_42 = []() { print_num(42); };
f_display_42();
// store the result of a call to std::bind
std::function<void()> f_display_31337 = std::bind(print_num, 31337);
f_display_31337();
// store a call to a member function
std::function<void(const Foo&, int)> f_add_display = &Foo::print_add;
Foo foo(314159);
f_add_display(foo, 1);
}