std::pmr::polymorphic_allocator<T>::allocate_bytes

 

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std::pmr::polymorphic_allocator

成员函数

polymorphic_allocator::polymorphic_allocator

polymorphic_allocator::allocate

polymorphic_allocator::deallocate

polymorphic_allocator::construct

polymorphic_allocator::destroy (C++20/26*)

polymorphic_allocator::allocate_bytes (C++20)

polymorphic_allocator::deallocate_bytes (C++20)

polymorphic_allocator::allocate_object (C++20)

polymorphic_allocator::deallocate_object (C++20)

polymorphic_allocator::new_object (C++20)

polymorphic_allocator::delete_object (C++20)

polymorphic_allocator::select_on_container_copy_construction

polymorphic_allocator::resource

非成员函数

operator==operator!= (直到 C++20)

 

void* allocate_bytes( std::size_t nbytes,                       std::size_t alignment = alignof(std::max_align_t) );		(自 C++20)

使用底层内存资源，在指定对齐方式 alignment 上分配 nbytes 字节的存储空间。等效于 return resource()->allocate(nbytes, alignment);.

参数

nbytes	-	要分配的字节数
alignment	-	要使用的对齐方式

返回值

指向分配的存储空间的指针。

注释

此函数是为了与完全特化的分配器 std::pmr::polymorphic_allocator<> 一起使用而引入的，但在任何特化中它都可能有用。

返回类型是 void*（而不是例如 std::byte*）以支持通过 static_cast<U*> 转换为任意指针类型 U*.

异常

可能会抛出调用 resource()->allocate.

另请参见

allocate_object (C++20)	分配适合对象或数组的原始内存 (公共成员函数)
new_object (C++20)	分配并构造一个对象 (公共成员函数)
allocate	分配内存 (公共成员函数)
allocate [静态]	使用分配器分配未初始化的存储空间 (std::allocator_traits<Alloc> 的公共静态成员函数)
allocate	分配内存 (std::pmr::memory_resource 的公共成员函数)