Destructuring and Tighter scopes with C++17

new-features.cpp

//  clang++ -ggdb -std=c++17 -fsanitize=address src/cool-features.cpp -o T
#include <cstdio>
#include <map>
#include <string>
#include <tuple>

using namespace std;

class record {
public:
  record(string a, string b) : result(a + "-" + b) {}
  string result;
};

int main() {
  const map<string, record> m = {{"Hello", {"A", "B"}}, {"Bar", {"C", "D"}}};

  for (const auto &[key, record] : m) {
    printf("Hello %s\n", record.result.c_str());
  }

  if (auto itr(m.find("Bar")); itr != m.end()) {
    const auto [key, record] = *itr;
    printf("Iterator dereference is valid here: %s\n", record.result.c_str());
  } else {
    // Couldn't find so can't use *itr here
  }
  enum class Colors { Red, Blue };

  auto producer = []() { return Colors::Red; };

  switch (auto result(producer()); result) {
  case Colors::Red:
    return printf("Got red\n");

  case Colors::Blue:
    return printf("Got Blue\n");
  }
}