Thepolymorphic_allocator::constructmember function doesuses-allocator construction, so that the elements of a container using apolymorphic_allocatorwill use that same allocator for their own allocations. For example, astd::pmr::vector<std::pmr::string>will use the samememory_resourcefor thevector's...
这种运行时多态性允许使用 polymorphic_allocator 的对象的行为就像它们在运行时使用不同的分配器类型一样,尽管它们具有相同的静态分配器类型 “常规”分配器的问题在于它们改变了容器的类型。如果你想要一个带有特定分配器的 vector ,你可以使用 Allocator 模板参数: auto my_vector = std::vector<int,my_allocator>(...
cppreference.com Create account std::pmr::polymorphic_allocator<T>::deallocate_object template<classU> voiddeallocate_object(U*p,std::size_tn=1); (since C++20) Deallocates the storage pointed to byp, which must have been allocated from astd::pmr::memory_resourcexthat compares equal to*resou...
std::allocator是无状态的,实测最简单的 allocator 只需要: value_type allocate deallocate rebind 目的是实现rebind(allocator<TypeA>, TypeB) == allocator<TypeB> C++11 已经使用 allocator_traits 实现了这种想法[1],并且 C++17 就抛弃了以前把 rebind 放到 allocator 内部实现的方法。 还有两个函数construct和...
allocates uninitialized storage using the allocator (public static member function of std::allocator_traits) allocate allocates memory (public member function of std::pmr::memory_resource) 代码语言:txt 复制 © cppreference.com 在CreativeCommonsAttribution下授权-ShareAlike未移植许可v3.0。
因此,移动polymorphic_allocator-使用容器可以抛出,并交换两个polymorphic_allocator-使用其分配器在未定义行为中不比较相同结果的容器。 另见 memory_resource (C++17) an abstract interface for classes that encapsulate memory resources (class) 代码语言:txt 复制 © cppreference.com 在CreativeCommonsAttribution下...
1) If std::uses_allocator<U, memory_resource*>::value==false (the type U does not use allocators) and std::is_constructible<U, Args...>::value==true, then constructs the object as if by ::new((void *) p) U(std::forward<Args>(args)... );. Otherwise...
std::pmr::polymorphic_allocator - cppreference.com用来控制内存分配的。比如如果你有个vector，但是你...
跟一般来说的类的多态有关系吗？怎么用？ std::pmr::polymorphic_allocator - cppreference.com和类的...
Main.cpp:32:11: note: in instantiation of member function 'phmap::priv::parallel_hash_set<4, raw_hash_set, phmap::NullMutex, phmap::priv::FlatHashMapPolicy<unsigned int, unsigned int>, std::hash, std::equal_to, std::experimental::pmr::polymorphic_allocator<std::pair<const unsigned int...