GenericForEach

GenericForEach.cpp

#include <iostream>
#include <string>
#include <functional>
#include <vector>
using namespace std;

#define StringArray std::vector<std::string>
#define ForEachMethod(a) std::function<void(const a&)>
#define ForEachTemplate(a, b) template<class a, class b>
#define ForEachString forEach<StringArray, string>

ForEachTemplate(ArrayType, ValueType)
void forEach(const ArrayType& arr, ForEachMethod(ValueType) callback) {
    for (auto entry : arr) {
        callback(entry);
    }
}

int main()
{
  StringArray strArr;
  strArr.push_back("a");
  strArr.push_back("b");
  strArr.push_back("c");
  strArr.push_back("d");
  strArr.push_back("e");
  
  ForEachString(strArr, [](const string& str) {
    cout << str << endl;
  });
}