⚙️ptr

This type is a literal pointer.

To preserve interoperability with C++, several functions return void* as the type, which then get converted to light_userdata. Since you can’t directly cast FFI types to light_userdata, we’ve introduced a specialized type helping with this conversion.

Before you convert your pointer to one that is supported by the API, you need to cast it to uintptr_t. This can be done in the following manner:

local ptr_num = ffi.cast('uintptr_t', ptr_cdata);

Then, you can use the cast value in this type's constructor.

__call

Constructor

Converts a number to pointer.

Arguments

Name	Type	Description
num	int	Pointer, as number.

Returns

Type	Description
ptr	Pointer, as light_userdata.

Example

-- cast to number first
local ptr_num = ffi.cast('uintptr_t', ptr_cdata);

-- then cast to light_userdata
local ptr_ld = ptr(ptr_num);