How to store objects without copy or move constructor in std::vector? 为了提高std::vector< T >的效率,它的基础数组需要预先分配,有时需要重新分配。但是,这需要使用复制ctor或move ctor创建和移动T类型的对象。 我遇到的问题是T无法复制或移动,因为它包含无法复制或移动的对象(例如
void process_elements(std::vector<MyType>& elements) noexcept { for(auto& elem : elements) { // Some complex processing on elem... } // Rearrange elements for next processing phase. std::sort(elements.begin(), elements.end()); } 在上面的例子中,如果 MyType 的移动构造函数和移动赋...
This example might be a little bit contrived--and of course you can find ways to avoid this kind of problem--for example, by storing and returning the vector by pointer, or by passing in a vector to be filled up. The thing is, neither of these programming styles is particularly natural...
vector<CSomeObjectWithMoveConstructor>vec1; cout<< "Adding first object to vector:"<< endl; vec1.push_back(CSomeObjectWithMoveConstructor(1024)); cout<< endl<< "Adding second object to vector:"<< endl; vec1.push_back(CSomeObjectWithMoveConstructor(1024)); g_bTraceOutput = false; cout<...
#include <iostream> #include <vector> using namespace std; // Move Class class Move { private: int* data; public: Move(int d) { data = new int; *data = d; cout << "Constructor is called for " << d << endl; }; // Move Constructor Move(Move&& source) : data{ source.data...
vectormsg {"Hello", "C++", "World", "from", "VS Code", "and the C++ extension!"}; for (const string& word : msg) { cout << word << " "; } cout << endl; } { // See https://go.microsoft.com/fwlink/?LinkId=733558 ...
C++ 标准始终禁止 const 元素(如 vector<const T> 或set<const T>)的容器。 Visual Studio 2013 及更早版本接受此类容器。 在当前版本中,此类容器无法编译。 std::allocator::deallocate 在Visual Studio 2013 和早期版本中,std::allocator::deallocate(p, n) 忽略了传入用于 n 的参数。 C++ 标准始终要求 n...
move的意义就在于直接把被拷贝者的数据移动过来,然后被拷贝者不再被使用。 在大部分STL容器中都实现了以右值引用为参数的移动构造函数和移动赋值重载函数。最常见的如std::vector的push_back和emplace_back。 std::forward 完美转发 虽然名字含义是转发,但他并不会做转发,同样也是做类型转换. std::forward<T>(u...
Copy constructors In both Visual Studio 2013 and Visual Studio 2015, the compiler generates a copy constructor for a class if that class has a user-defined move constructor but no user-defined copy constructor. In Dev14, this implicitly generated copy constructor is also marked "= delete".main...
Copy constructors In both Visual Studio 2013 and Visual Studio 2015, the compiler generates a copy constructor for a class if that class has a user-defined move constructor but no user-defined copy constructor. In Dev14, this implicitly generated copy constructor is also marked "= delete".main...