modern-cpp-tutorial/code/2/2.3.if.switch.cpp

//
// 2.3.if.switch.cpp
// chapter 2 language usability
// modern cpp tutorial
//
// created by changkun at changkun.de
//

#include <iostream>
#include <vector>
#include <algorithm>

int main() {
    std::vector<int> vec = {1, 2, 3, 4};

    // before c++17, can be simplefied by using `auto`
    const std::vector<int>::iterator itr = std::find(vec.begin(), vec.end(), 2);
    if (itr != vec.end()) {
        *itr = 3;
    }

    // after c++17, can be simplefied by using `auto`
    if (const std::vector<int>::iterator itr = std::find(vec.begin(), vec.end(), 3);
        itr != vec.end()) {
        *itr = 4;
    }

    // should output: 1, 4, 3, 4. can be simplefied using `auto`
    for (std::vector<int>::iterator element = vec.begin(); element != vec.end(); ++element)
        std::cout << *element << std::endl;
}