Struct tlua::CDataOnStack

pub struct CDataOnStack<'l, L> { /* private fields */ }

A cdata value stored on lua stack. Can be used to check type of cdata, access the raw bytes of the data, downcast it to a rust type or passed as an argument into a lua function.

Examples:

use tlua::{CDataOnStack, Lua, ffi};
let lua = Lua::new();
let cdata: CDataOnStack<_> = lua.eval("
    ffi = require 'ffi';
    return ffi.new('uint8_t', 69)
").unwrap();

// check CTypeID
assert_eq!(cdata.ctypeid(), ffi::CTID_UINT8);
// check raw bytes
assert_eq!(cdata.data(), [69]);

// pass to a lua function
let n: u8 = lua.eval_with("return ... + 1", &cdata).unwrap();
assert_eq!(n, 70);

Implementations

impl<L> CDataOnStack<'_, L>

where L: AsLua,

pub fn as_ptr(&self) -> *const c_void

Return pointer to data. Maybe use CDataOnStack::data instead.

pub fn try_as_bytes(&self) -> Option<&[u8]>

Return a slice of bytes covering the data if the data’s size was already retrieved before. Otherwise return None.

See also CDataOnStack::data.

pub fn try_as_bytes_mut(&mut self) -> Option<&mut [u8]>

Return a mutable slice of bytes covering the data if the data’s size was already retrieved before. Otherwise return None.

See also CDataOnStack::data_mut.

pub fn data(&self) -> &[u8]

Return a slice of bytes covering the data. Calling this function the first time around will perform an expensive operation of retrieving the data’s size. So if for some reason you just need the pointer to the data, use the CDataOnStack::as_ptr. But if you actually need the bytes, use this function.

pub fn data_mut(&mut self) -> &mut [u8]

Return a mutable slice of bytes covering the data. Calling this function the first time around will perform an expensive operation of retrieving the data’s size.

pub fn ctypeid(&self) -> CTypeID

Return the ctypeid of the cdata.

pub fn try_downcast<T>(&self) -> Option<&T>

where T: AsCData,

Return a reference to the underlying value if self.ctypeid() == <T as AsCData>::ctypeid(), otherwise return None.

This function may panic, if self.data().len() != std::mem::size_of::<T>()

pub fn try_downcast_mut<T>(&self) -> Option<&mut T>

where T: AsCData,

Return a mutable reference to the underlying value if self.ctypeid() == <T as AsCData>::ctypeid(), otherwise return None.

This function may panic, if self.data().len() != std::mem::size_of::<T>()

pub fn try_downcast_into<T>(self) -> Result<T, Self>

where T: AsCData,

Return the underlying value consuming self if self.ctypeid() == <T as AsCData>::ctypeid(), otherwise return Err(self).

This function may panic, if self.data().len() != std::mem::size_of::<T>()

Trait Implementations

impl<L> AsLua for CDataOnStack<'_, L>

where L: AsLua,

fn as_lua(&self) -> LuaState

fn try_push<T>( self, v: T ) -> Result<PushGuard<Self>, (<T as PushInto<Self>>::Err, Self)>

where Self: Sized, T: PushInto<Self>,

Try to push v onto the lua stack.

fn push<T>(self, v: T) -> PushGuard<Self>

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

Push v onto the lua stack.

fn try_push_one<T>( self, v: T ) -> Result<PushGuard<Self>, (<T as PushInto<Self>>::Err, Self)>

where Self: Sized, T: PushOneInto<Self>,

Try to push v onto the lua stack.

fn push_one<T>(self, v: T) -> PushGuard<Self>

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

Push v onto the lua stack.

fn push_iter<I>(self, iterator: I) -> Result<PushGuard<Self>, Self>

where Self: Sized, I: Iterator, <I as Iterator>::Item: PushInto<LuaState>, <<I as Iterator>::Item as PushInto<LuaState>>::Err: Into<Void>,

Push iterator onto the lua stack as a lua table.

fn try_push_iter<I>( self, iterator: I ) -> Result<PushGuard<Self>, (PushIterErrorOf<I>, Self)>

where Self: Sized, I: Iterator, <I as Iterator>::Item: PushInto<LuaState>,

Push iterator onto the lua stack as a lua table.

fn read<T>(self) -> ReadResult<T, Self>

where Self: Sized, T: LuaRead<Self>,

fn read_at<T>(self, index: i32) -> ReadResult<T, Self>

where Self: Sized, T: LuaRead<Self>,

fn read_at_nz<T>(self, index: NonZeroI32) -> ReadResult<T, Self>

where Self: Sized, T: LuaRead<Self>,

fn pcall<F, R>(&self, f: F) -> Result<R, LuaError>

where F: FnOnce(StaticLua) -> R,

Call a rust function in protected mode. If a lua error is thrown during execution of f the function will return a LuaError.

impl<'l, L: Debug> Debug for CDataOnStack<'l, L>

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

Formats the value using the given formatter.

impl<'a, L> From<CDataOnStack<'a, L>> for Object<L>

fn from(ud: CDataOnStack<'a, L>) -> Self

Converts to this type from the input type.

impl<L> LuaRead<L> for CDataOnStack<'_, L>

where L: AsLua,

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<L, O> Push<L> for CDataOnStack<'_, O>

where L: AsLua, O: AsLua,

type Err = Void

Error that can happen when pushing a value.

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

Pushes the value on the top of the stack.

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

where <Self as Push<L>>::Err: Into<Void>,

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

impl<L> TryFrom<Object<L>> for CDataOnStack<'_, L>

where L: AsLua,

type Error = Object<L>

The type returned in the event of a conversion error.

fn try_from(o: Object<L>) -> Result<Self, Self::Error>

Performs the conversion.