因为可能发生再分配,emplace_back 对vector 要求元素类型可移动插入 (MoveInsertable) 。 示例下列代码用 emplace_back 追加President 类型的对象到 std::vector。它演示 emplace_back 如何转发参数给 President 的构造函数,并展示如何用 emplace_back 避免用 push_back 时的额外复制或移动操作。 运行此代码 #include...
template< class... Args > reference emplace_back( Args&&... args ); (C++17 起) (C++26 起为 constexpr) 添加新元素到容器尾。元素通过 std::allocator_traits::construct 构造,通常用布置 new 在容器所提供的位置原位构造元素。实参 args... 以std::forward<Args>(args)... 转发到构造函数。
deque::push_back deque::emplace_back (C++11) deque::append_range (C++23) deque::pop_back deque::resize deque::swap Non-member functions operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20) ...
cout<<"emplace_back:\n";auto&ref=elections.emplace_back("Nelson Mandela","South Africa",1994);assert(ref.year==1994&&"uses a reference to the created object (C++17)");std::list<President>reElections;std::cout<<"\npush_back:\n";reElections.push_back(President("Franklin Delano Roosevelt...
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push_back ajoute des éléments à la fin Original: adds elements to the end The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction membre publique) [edit] emplace_back (C++11) construit des ...
问std::memory_order_relaxed示例在cppreference.com中EN在 C++ 编程中，有时候我们需要在不进行拷贝的...
emplace_back (C++11) baut Elemente-Platz am Ende Original: constructs elements in-place at the end The text has been machine-translated viaGoogle Translate. You can help to correct and verify the translation. Clickherefor instructions.
std::vector<T,Allocator>::emplace_back From cppreference.com <cpp |container |vector std::vector Member types Member functions vector::vector vector::~vector vector::operator= vector::assign vector::assign_range (C++23) vector::get_allocator ...
unchecked_emplace_back("\N{CAT}", std::move(dog)); std::println("fauna = {}", fauna); // fauna.unchecked_emplace_back("BUG", "BUG"); // undefined behavior: no space } Output: fauna = [("🐈", "🐕"), ("🐈", "🐕")]...