Example to show the speed difference of using an iterator across an array, versus using std::begin() iteration. Source: https://softwareengineering.stackexchange.com/questions/386614/c-iterator-why-is-there-no-iterator-base-class-all-iterators-inherit-from

iterator_test.cpp

/* Iterator Example
 * Modified to support clang compiler
 * Compiler and Run: 
 * $ clang++ -Wall -Ofast -std=c++11 iterator_test.cpp && ./a.out                                       
 * y
 * y
 * time1: 143ns
 * time2: 168ns
 * https://softwareengineering.stackexchange.com/questions/386614/c-iterator-why-is-there-no-iterator-base-class-all-iterators-inherit-from
 */
#include <chrono>
#include <iostream>
#include <algorithm>

template <class T>
class iterator_base {
public:
    virtual T &operator*() = 0;
    virtual iterator_base &operator++() = 0;
    virtual bool operator==(iterator_base const &other) { return pos == other.pos; }
    virtual bool operator!=(iterator_base const &other) { return pos != other.pos; }
    iterator_base(T *pos) : pos(pos) {}
protected:
    T *pos;
};

template <class T>
class array_iterator : public iterator_base<T> {
    using iterator_base<T>::pos;
  public:
    virtual T &operator*() override { return *pos; }
    virtual array_iterator &operator++() override { ++pos; return *this; }
    array_iterator(T *pos) : iterator_base<T>(pos) {}
};

int main() {
    char input[] = "asdfasdfasdfasdfasdfasdfasdfadsfasdqwerqwerqwerqrwertytyuiyuoiiuoThis is a stringy to search for something";
    using namespace std::chrono;

    auto start1 = high_resolution_clock::now();
    auto pos = std::find(std::begin(input), std::end(input), 'g');
    auto stop1 = high_resolution_clock::now();

    std::cout << *++pos << "\n";

    auto start2 = high_resolution_clock::now();
    auto pos2 = std::find(array_iterator<char>(input), array_iterator<char>(input+sizeof(input)), 'g');
    auto stop2 = high_resolution_clock::now();

    std::cout << *++pos2 << "\n";

    std::cout << "time1: " << duration_cast<nanoseconds>(stop1 - start1).count() << "ns\n";
    std::cout << "time2: " << duration_cast<nanoseconds>(stop2 - start2).count() << "ns\n";
}