An example usage of the points-to-member access operator in C++

sumOfMembers.cpp

#include <iostream>
#include <vector>

template <typename MemberType0, typename MemberType1>
struct S {
	MemberType0 m0;
	MemberType1 m1;

	S(MemberType0 arg_m0, MemberType1 arg_m1) : m0(arg_m0), m1(arg_m1) {}
};

template <typename ContainerType, typename MemberType>
MemberType sumOfMembers(ContainerType& struct_v, MemberType ContainerType::value_type::* member_name) {
	MemberType result = MemberType();

	for (auto& s : struct_v) {
		result += s.*member_name;
	}

	return result;
}

int main(int argc, char** argv) {
	typedef S<int, double> SP;

	std::vector< S<int, double> > struct_v;
	struct_v.push_back( SP(1, 2.0) );
	struct_v.push_back( SP(3, 4.0) );
	struct_v.push_back( SP(5, 6.0) );

	std::cout << "Sum of m0: " << sumOfMembers(struct_v, &SP::m0) << std::endl;
	std::cout << "Sum of m1: " << sumOfMembers(struct_v, &SP::m1) << std::endl;

	return 0;
}