nngn::lua::user_data< T > Class Template Reference

Data block allocated for user data objects. More...

#include <user.h>

Inheritance diagram for nngn::lua::user_data< T >:

Collaboration diagram for nngn::lua::user_data< T >:

Public Types
using	get_type = std::remove_pointer_t<T>*

Public Member Functions
	user_data (const T &x)
	Creates a non-owning (reference) object.
	user_data (T &&x)
	Creates an owning (copy) object.
get_type	get (void) const
	Pointer to the contained/referenced object.
void	destroy (void)
	Destroys the T value if this is an owning user data value.

Static Public Member Functions
static get_type	get (state_view lua, int i)
	Retrieves a user data of type T from the stack.
static get_type	from_light (const void *p)
	Retrieves a user data of type T from a light user data value.
static bool	check_type (state_view lua, int i)
	Verifies that the value on the stack is a user data of type T.
static table	push_metatable (state_view lua)
	Pushes the type's meta table onto the stack.
static int	gc (lua_State *L)
	Function to be used as a user data's __gc meta-method.
static int	eq (lua_State *L)
	Function to be used as a user data's __eq meta-method.
template<typename R >
static int	push (state_view lua, R &&r)
	Pushes a value on the stack as a user data of type T.

Private Types
using	header_type = user_data_header<T>
using	base_type = typename alloc_block<header_type, T>::storage
Private Types inherited from nngn::alloc_block< H, T >::storage
using	parent = alloc_block

Static Private Member Functions
static get_type	get_pointer (state_view lua, int i)
Static Private Member Functions inherited from nngn::lua::detail::user_data_base
static table	push_metatable (state_view lua, std::string_view meta)
	Pushes the table stored as meta in the global table.
static bool	check_type (state_view lua, int i, std::string_view meta)
static bool	check_pointer_type (state_view lua, int i, std::string_view meta)

Static Private Attributes
static constexpr auto	meta

Friends
class	user_data< T * >

Additional Inherited Members
Private Attributes inherited from nngn::alloc_block< H, T >::storage
header_type	header = {}
value_type	data = {}

Detailed Description

template<typename T>
class nngn::lua::user_data< T >

Data block allocated for user data objects.

This object is owning (i.e. must be destroyed / garbage collected) if header.p points to data. Otherwise,header.p points to an existing (external) object and no space is allocated for data.

Member Typedef Documentation

base_type

template<typename T >

using nngn::lua::user_data< T >::base_type = typename alloc_block<header_type, T>::storage

private

get_type

template<typename T >

using nngn::lua::user_data< T >::get_type = std::remove_pointer_t<T>*

header_type

template<typename T >

using nngn::lua::user_data< T >::header_type = user_data_header<T>

private

Constructor & Destructor Documentation

user_data() [1/2]

template<typename T >

nngn::lua::user_data< T >::user_data ( const T & x )

explicit

Creates a non-owning (reference) object.

user_data() [2/2]

template<typename T >

nngn::lua::user_data< T >::user_data ( T && x )

explicit

Creates an owning (copy) object.

Member Function Documentation

check_type()

template<typename T >

static bool nngn::lua::user_data< T >::check_type ( state_view lua, int i )

static

Verifies that the value on the stack is a user data of type T.

destroy()

template<typename T >

void nngn::lua::user_data< T >::destroy

(

void

)

Destroys the T value if this is an owning user data value.

This is done when the value was initially pushed as a value / rvalue reference type.

See also

push

eq()

template<typename T >

static int nngn::lua::user_data< T >::eq ( lua_State * L )

static

Function to be used as a user data's __eq meta-method.

Compares objects by identity (i.e. address).

mt["__eq"] = &user_data<T>::eq;

from_light()

template<typename T >

static get_type nngn::lua::user_data< T >::from_light ( const void * p )

static

Retrieves a user data of type T from a light user data value.

No type verification is performed.

Parameters

p	Must be a pointer to an object in the same format as what is pushed by push.

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gc()

template<typename T >

static int nngn::lua::user_data< T >::gc ( lua_State * L )

static

Function to be used as a user data's __gc meta-method.

E.g.:

mt["__gc"] = &user_data<T>::gc;

get() [1/2]

template<typename T >

static get_type nngn::lua::user_data< T >::get ( state_view lua, int i )

static

Retrieves a user data of type T from the stack.

get() [2/2]

template<typename T >

get_type nngn::lua::user_data< T >::get ( void ) const

inline

Pointer to the contained/referenced object.

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get_pointer()

template<typename T >

static get_type nngn::lua::user_data< T >::get_pointer ( state_view lua, int i )

staticprivate

push()

template<typename T >

template<typename R >

static int nngn::lua::user_data< T >::push ( state_view lua, R && r )

static

Pushes a value on the stack as a user data of type T.

R may be either a pointer, reference, or value type. For pointers and lvalue references, the user data is a reference to an existing value. For value or rvalue references, the user data is pushed as an independent copy of the value.

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push_metatable()

template<typename T >

static table nngn::lua::user_data< T >::push_metatable ( state_view lua )

static

Pushes the type's meta table onto the stack.

Friends And Related Symbol Documentation

user_data< T * >

template<typename T >

friend class user_data< T * >

friend

Member Data Documentation

meta

template<typename T >

auto nngn::lua::user_data< T >::meta

staticconstexprprivate

Initial value:

=
        nngn::lua::metatable_name<
            std::remove_const_t<std::remove_pointer_t<T>>>

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The documentation for this class was generated from the following file:

• src/lua/user.h