Module ext_php_rs::boxed

A pointer type for heap allocation using the Zend memory manager.

Heap memory in PHP is usually request-bound and allocated inside memory arenas, which are cleared at the start and end of a PHP request. Allocating and freeing memory that is allocated on the Zend heap is done through two separate functions efree and emalloc.

As such, most heap-allocated PHP types cannot be allocated on the stack, such as ZendStr, which is a dynamically-sized type, and therefore must be allocated on the heap. A regular Box would not work in this case, as the memory needs to be freed from a separate function zend_string_release. The ZBox type provides a wrapper which calls the relevant release functions based on the type and what is inside the implementation of ZBoxable.

This type is not created directly, but rather through a function implemented on the downstream type. For example, ZendStr has a function new which returns a ZBox<ZendStr>.

Structs

ZBox

A pointer type for heap allocation using the Zend memory manager.

Traits

ZBoxable

Implemented on types that can be heap allocated using the Zend memory manager. These types are stored inside a ZBox when heap-allocated, and the free method is called when the box is dropped.