C++中如何使用元组优化返回_多返回值处理

#include <iostream>
#include <tuple>
#include <string>

std::tuple<int, double, std::string> process_data(int input) {
  // 模拟一些计算
  int result_int = input * 2;
  double result_double = static_cast<double>(input) / 3.0;
  std::string result_string = "Result: " + std::to_string(input);

  return std::make_tuple(result_int, result_double, result_string);
}

int main() {
  // 使用 std::tie 解包元组
  int int_val;
  double double_val;
  std::string string_val;
  std::tie(int_val, double_val, string_val) = process_data(10);
  std::cout << "Int: " << int_val << ", Double: " << double_val << ", String: " << string_val << std::endl;

  // 使用结构化绑定 (C++17)
  auto [int_val2, double_val2, string_val2] = process_data(20);
  std::cout << "Int: " << int_val2 << ", Double: " << double_val2 << ", String: " << string_val2 << std::endl;

  // 使用 std::get 访问元组元素
  auto result = process_data(30);
  std::cout << "Int: " << std::get<0>(result) << ", Double: " << std::get<1>(result) << ", String: " << std::get<2>(result) << std::endl;

  return 0;
}

#include <iostream>
#include <tuple>

std::tuple<int, double, std::string> get_values() {
    return std::make_tuple(1, 2.5, "hello");
}

int main() {
    int a;
    std::string c;
    std::tie(a, std::ignore, c) = get_values(); // 忽略 double 值
    std::cout << "a = " << a << ", c = " << c << std::endl;

    auto [x, y, z] = get_values(); // 获取所有值
    std::cout << "x = " << x << ", y = " << y << ", z = " << z << std::endl;

    return 0;
}

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

std::tuple<int, int> find_min_max(const std::vector<int>& data) {
  if (data.empty()) {
    return std::make_tuple(0, 0); // 或者抛出异常
  }
  int min_val = data[0];
  int max_val = data[0];
  for (int val : data) {
    min_val = std::min(min_val, val);
    max_val = std::max(max_val, val);
  }
  return std::make_tuple(min_val, max_val);
}

int main() {
  std::vector<int> numbers = {5, 2, 8, 1, 9};
  auto [min_value, max_value] = find_min_max(numbers);
  std::cout << "Min: " << min_value << ", Max: " << max_value << std::endl;
  return 0;
}