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 ex
类模板std::pmr::polymorphic_allocator是Allocator其分配行为取决于它所用的内存资源。因此,不同的实例polymorphic_allocator会表现出完全不同的分配行为。此运行时多态性允许对象使用polymorphic_allocator如果它们在运行时使用不同的分配器类型,而不考虑相同的静态分配器类型,则要执行此操作。
来自cppreference 的选择报价: 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...
From cppreference.com <cpp |experimental |polymorphic allocator C++ Polymorphic allocator library polymorphic_allocator Convenience aliases for containers usingpolymorphic_allocator Memory resource classes memory_resource synchronized_pool_resource
Categories: C-CPP custom allocator 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...
operators (std::allocator) operators (std::scoped_allocator_adaptor) std::allocator std::allocator::address std::allocator::allocate std::allocator::allocator std::allocator::construct std::allocator::deallocate std::allocator::destroy std::allocator::max_size std::allocator_traits std::allocator_...
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...
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...
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...