//
// 4.1.linear.container.cpp
// modern c++ tutorial
//
// created by changkun at changkun.de
// https://github.com/changkun/modern-cpp-tutorial
//

#include <iostream>
#include <array>
#include <vector>

void foo(int *p, int len) {
 for (int i = 0; i != len; ++i) {
 std::cout << p[i] << std::endl;
 }
}

int main() {
 std::vector<int> v;
 std::cout << "size:" << v.size() << std::endl; // output 0
 std::cout << "capacity:" << v.capacity() << std::endl; // output 0

 // As you can see, the storage of std::vector is automatically managed and 
 // automatically expanded as needed.
 // But if there is not enough space, you need to redistribute more memory, 
 // and reallocating memory is usually a performance-intensive operation.
 v.push_back(1);
 v.push_back(2);
 v.push_back(3);
 std::cout << "size:" << v.size() << std::endl; // output 3
 std::cout << "capacity:" << v.capacity() << std::endl; // output 4

 // The auto-expansion logic here is very similar to Golang's slice.
 v.push_back(4);
 v.push_back(5);
 std::cout << "size:" << v.size() << std::endl; // output 5
 std::cout << "capacity:" << v.capacity() << std::endl; // output 8

 // As can be seen below, although the container empties the element, 
 // the memory of the emptied element is not returned.
 v.clear(); 
 std::cout << "size:" << v.size() << std::endl; // output 0
 std::cout << "capacity:" << v.capacity() << std::endl; // output 8

 // Additional memory can be returned to the system via the shrink_to_fit() call
 v.shrink_to_fit();
 std::cout << "size:" << v.size() << std::endl; // output 0
 std::cout << "capacity:" << v.capacity() << std::endl; // output 0


 std::array<int, 4> arr= {1,4,3,2};
 
 //int len = 4;
 //std::array<int, len> arr = {1,2,3,4}; // illegal, size of array must be constexpr
 
 // C style parameter passing
 // foo(arr, arr.size()); // illegal, cannot convert implicitly
 foo(&arr[0], arr.size());
 foo(arr.data(), arr.size());

 // more usage
 std::sort(arr.begin(), arr.end());
 for(auto &i : arr)
 std::cout << i << std::endl;
 
 return 0;
}