Modern-CPP - Chapter03 - Containers

课程来源：b站我是龙套小果丁

1. template <typename Range> void Function(Range &range) {
     for (auto &elem : range) {
       elem *= 2;
     }
   }
   

2. #include <iostream>
   #include <iterator>
   #include <ostream>
   #include <vector>
      
   void print_vector(const std::vector<int> &v) {
     std::copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " "));
     std::cout << std::endl;
   }
      
   int main() {
     std::vector v1(10, 5);
     std::vector v2{2, 1, 4};
      
     v1.insert(v1.begin() + 2, v2.rbegin(), v2.rend());
      
     v1.erase(v1.begin() + 5, v1.end());
      
     v1.erase(
         std::remove_if(v1.begin(), v1.end(), [](int x) { return x % 2 == 1; }),
         v1.end());
     std::vector v3{1, 7};
      
     auto result = v1 <=> v3;
     if (std::is_lt(result))
       std::println("v1 <=> v3: less");
     else if (std::is_gt(result))
       std::println("v1 <=> v3: greater");
     else
       std::println("v1 <=> v3: equal");
   }
   

3. std::list l1(10, 5);
   std::list l2{2, 1, 4};
   l1.splice(l1.end(), l2, l2.begin(), l2.end());
   l1.unique();
   l1.sort();
   

4. No, because deque’s typical implementation is using a dynamic circular queue whose elements are pointers. These pointers points to contiguous memory but there’s no single contiguous memory that could be returned by a .data() method that would give access to all elements.

5. 后插入的情况有可能因为容量不够导致重分配，从而使迭代器失效

6. 最开始it指向vec中的第一个10。erase函数的内部实现是remove，而remove会把所有不等于it指向的元素前移：

   [10, 2, 3 ,10, 4], it -> 10
   [2, 10, 3, 10, 4], it -> 2
   [2, 3, 10, 10, 4], it -> 2
   [2, 3, 10, 4, 10], it -> 2
   

   it所指向的值在过程中发生改变，因此造成错误