Struct tlua::CData

pub struct CData<T>(pub T)
where
    T: AsCData;

CData A wrapper type for reading/writing rust values as luajit cdata.

use tlua::{Lua, CData};
let lua = Lua::new();
lua.set("cdata", CData(1337_i16));
let ty: String = lua.eval("return require('ffi').typeof(cdata)").unwrap();
assert_eq!(ty, "ctype<short>");

let CData(num): CData<i16> = lua.get("cdata").unwrap();
assert_eq!(num, 1337);

For this to work the type must implement AsCData which is true for builtin numbers and some pointers but can also be implemented for user defined types:

use tlua::{AsCData, CData};
use tlua::{Lua, AsLua, ffi, c_ptr};

#[repr(C)]
#[derive(Debug, PartialEq, Clone, Copy)]
struct S { i: i32, f: f32 }

// let luajit know about our struct
lua.exec("ffi.cdef[[ struct S { int i; float f; }; ]]").unwrap();

// save the CTypeID of our struct
static mut CTID_STRUCT_S: Option<ffi::CTypeID> = None;
let ctid = unsafe { ffi::luaL_ctypeid(lua.as_lua(), c_ptr!("struct S")) };
unsafe { CTID_STRUCT_S = Some(ctid) }

// implement AsCData for our struct so that it can be wrapped with CData
unsafe impl AsCData for S {
    fn ctypeid() -> ffi::CTypeID {
        unsafe { CTID_STRUCT_S.unwrap() }
    }
}

// wirte our struct into a lua variable as cdata
lua.set("tmp", CData(S { i: 69, f: 420.0 }));

// check it's type
let ty: String = lua.eval("return type(tmp)").unwrap();
assert_eq!(ty, "cdata");

// read the value back
let CData(res): CData<S> = lua.get("tmp").unwrap();
assert_eq!(res, S { i: 69, f: 420.0 });

Tuple Fields

0: T

Trait Implementations

impl<T> Clone for CData<T>

where T: AsCData + Clone,

fn clone(&self) -> CData<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for CData<T>

where T: AsCData + Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Hash for CData<T>

where T: AsCData + Hash,

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<L, T> LuaRead<L> for CData<T>

where L: AsLua, T: AsCData,

fn lua_read_at_position(lua: L, index: NonZeroI32) -> ReadResult<Self, L>

Reads the data from Lua at a given position.

fn n_values_expected() -> i32

fn lua_read(lua: L) -> ReadResult<Self, L>

Reads the data from Lua.

fn lua_read_at_maybe_zero_position(lua: L, index: i32) -> ReadResult<Self, L>

where L: AsLua,

impl<T> Ord for CData<T>

where T: AsCData + Ord,

fn cmp(&self, other: &CData<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<T> PartialEq for CData<T>

where T: AsCData + PartialEq,

fn eq(&self, other: &CData<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> PartialOrd for CData<T>

where T: AsCData + PartialOrd,

fn partial_cmp(&self, other: &CData<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<L, T> PushInto<L> for CData<T>

where L: AsLua, T: AsCData,

type Err = Void

fn push_into_lua(self, lua: L) -> Result<PushGuard<L>, (Self::Err, L)>

Push the value into lua by value

fn push_into_no_err(self, lua: L) -> PushGuard<L>

where Self: Sized, <Self as PushInto<L>>::Err: Into<Void>,

Same as push_into_lua but can only succeed and is only available if Err implements Into<Void>.

impl<T> Copy for CData<T>

where T: AsCData + Copy,

impl<T> Eq for CData<T>

where T: AsCData + Eq,

impl<L, T> PushOneInto<L> for CData<T>

where L: AsLua, T: AsCData + Copy,

impl<T> StructuralEq for CData<T>

where T: AsCData,

impl<T> StructuralPartialEq for CData<T>

where T: AsCData,