Struct cpp_core::Ref

pub struct Ref<T>(_);

A non-null, mutable pointer to a C++ object (similar to a C++ reference).

Ref never owns its content.

Note that unlike Rust references, Ref can be freely copied, producing multiple mutable pointers to the same object, which is usually necessary to do when working with C++ libraries.

Ref implements operator traits and delegates them to the corresponding C++ operators. This means that you can use &ptr + value to access the object's operator+.

Ref implements Deref and DerefMut, allowing to call the object's methods directly. In addition, methods of the object's first base class are also directly available thanks to nested Deref implementations.

If the object provides an iterator interface through begin() and end() functions, Ref will implement IntoIterator, so you can iterate on it directly.

Safety

It's not possible to automatically track the ownership of objects possibly managed by C++ libraries. The user must ensure that the object is alive while Ref exists. Note that with Ref, it's possible to call unsafe C++ code without using any more unsafe Rust code, for example, by using operator traits, so care should be taken when exposing Ref in a safe interface.

Methods

impl<T> Ref<T>

pub unsafe fn new(ptr: Ptr<T>) -> Option<Self>

Creates a Ref from a Ptr. Returns None if ptr is null.

Safety

ptr must be valid. See type level documentation.

pub unsafe fn from_raw(ptr: *const T) -> Option<Self>

Creates a Ref from a raw pointer. Returns None if ptr is null.

Safety

ptr must be valid. See type level documentation.

pub unsafe fn from_raw_ref(value: &T) -> Self

Creates a Ref from a raw reference.

Safety

value must be alive as long as Ref or pointers derived from it are used. See type level documentation.

pub unsafe fn from_raw_non_null(ptr: NonNull<T>) -> Self

Creates a Ref from a non-null pointer.

Safety

ptr must be valid. See type level documentation.

pub unsafe fn as_ptr(self) -> Ptr<T>

Converts self to a Ptr.

Safety

self must be valid. See type level documentation.

pub fn as_raw_ptr(self) -> *const T

Returns constant raw pointer to the value.

pub unsafe fn static_upcast<U>(self) -> Ref<U> where
    T: StaticUpcast<U>, 

Converts the pointer to the base class type U.

Safety

This operation is safe as long as self is valid.

pub unsafe fn static_downcast<U>(self) -> Ref<U> where
    T: StaticDowncast<U>, 

Converts the pointer to the derived class type U.

It's recommended to use dynamic_cast instead because it performs a checked conversion.

Safety

This operation is safe as long as self is valid and it's type is U or inherits from U.

pub unsafe fn dynamic_cast<U>(self) -> Option<Ref<U>> where
    T: DynamicCast<U>, 

Converts the pointer to the derived class type U. Returns None if the object's type is not U and doesn't inherit U.

Safety

This operation is safe as long as self is valid.

pub unsafe fn begin(self) -> <&'static T as Begin>::Output where
    &'static T: Begin, 

Returns a C++ const iterator object pointing to the beginning of the collection.

It's recommended to iterate directly on a Ref<T> when possible, using automatic IntoIterator implementation.

Safety

self must be valid. It's not possible to make any guarantees about safety, since this function calls arbitrary C++ library code.

pub unsafe fn end(self) -> <&'static T as End>::Output where
    &'static T: End, 

Returns a C++ const iterator object pointing to the end of the collection.

It's recommended to iterate directly on a Ref<T> when possible, using automatic IntoIterator implementation.

Safety

self must be valid. It's not possible to make any guarantees about safety, since this function calls arbitrary C++ library code.

pub unsafe fn as_slice<'a, T1>(self) -> &'a [T1] where
    T: 'static,
    &'static T: Begin<Output = Ptr<T1>> + End<Output = Ptr<T1>>, 

Returns a slice corresponding to the object. This function is available when begin() and end() functions of the object return pointers.

Safety

self must be valid. It's not possible to make any guarantees about safety, since this function calls arbitrary C++ library code. It's not recommended to store the slice because it may be modified by the C++ library, which would violate Rust's aliasing rules.

Trait Implementations

impl<T, U> CastFrom<Ref<U>> for Ptr<T> where
    U: StaticUpcast<T>, 

unsafe fn cast_from(value: Ref<U>) -> Self

Performs the conversion.

impl<T, U> CastFrom<MutRef<U>> for Ref<T> where
    U: StaticUpcast<T>, 

unsafe fn cast_from(value: MutRef<U>) -> Self

Performs the conversion.

impl<'a, T, U: CppDeletable> CastFrom<&'a CppBox<U>> for Ref<T> where
    U: StaticUpcast<T>, 

unsafe fn cast_from(value: &'a CppBox<U>) -> Self

Performs the conversion.

impl<T, U> CastFrom<Ref<U>> for Ref<T> where
    U: StaticUpcast<T>, 

unsafe fn cast_from(value: Ref<U>) -> Self

Performs the conversion.

impl<T> Clone for Ref<T>

Creates another pointer to the same object.

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T, U> PartialOrd<U> for Ref<T> where
    T: Lt<U> + Le<U> + Gt<U> + Ge<U> + PartialEq<U>, 

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

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

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

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

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

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

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

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

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

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

impl<T> Copy for Ref<T>

Creates another pointer to the same object.

impl<T, T1, T2> IntoIterator for Ref<T> where
    T: 'static,
    &'static T: Begin<Output = CppBox<T1>> + End<Output = CppBox<T2>>,
    T1: CppDeletable + PartialEq<Ref<T2>> + 'static,
    T2: CppDeletable,
    &'static T1: Indirection,
    &'static mut T1: Increment, 

type Item = <&'static T1 as Indirection>::Output

The type of the elements being iterated over.

type IntoIter = CppIterator<T1, T2>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T, U> PartialEq<U> for Ref<T> where
    T: PartialEq<U>, 

fn eq(&self, rhs: &U) -> bool

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

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T> Deref for Ref<T>

Allows to call member functions of T and its base classes directly on the pointer.

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T> Debug for Ref<T>

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

Formats the value using the given formatter.

impl<T: 'static, U> Sub<U> for Ref<T> where
    &'static T: Sub<U>, 

type Output = <&'static T as Sub<U>>::Output

The resulting type after applying the - operator.

fn sub(self, rhs: U) -> Self::Output

Performs the - operation.

impl<T: 'static, U> Rem<U> for Ref<T> where
    &'static T: Rem<U>, 

type Output = <&'static T as Rem<U>>::Output

The resulting type after applying the % operator.

fn rem(self, rhs: U) -> Self::Output

Performs the % operation.

impl<T: 'static, U> Div<U> for Ref<T> where
    &'static T: Div<U>, 

type Output = <&'static T as Div<U>>::Output

The resulting type after applying the / operator.

fn div(self, rhs: U) -> Self::Output

Performs the / operation.

impl<T: 'static, U> Add<U> for Ref<T> where
    &'static T: Add<U>, 

type Output = <&'static T as Add<U>>::Output

The resulting type after applying the + operator.

fn add(self, rhs: U) -> Self::Output

Performs the + operation.

impl<T: 'static, U> Mul<U> for Ref<T> where
    &'static T: Mul<U>, 

type Output = <&'static T as Mul<U>>::Output

The resulting type after applying the * operator.

fn mul(self, rhs: U) -> Self::Output

Performs the * operation.

impl<T: 'static, U> BitAnd<U> for Ref<T> where
    &'static T: BitAnd<U>, 

type Output = <&'static T as BitAnd<U>>::Output

The resulting type after applying the & operator.

fn bitand(self, rhs: U) -> Self::Output

Performs the & operation.

impl<T: 'static, U> BitOr<U> for Ref<T> where
    &'static T: BitOr<U>, 

type Output = <&'static T as BitOr<U>>::Output

The resulting type after applying the | operator.

fn bitor(self, rhs: U) -> Self::Output

Performs the | operation.

impl<T: 'static, U> BitXor<U> for Ref<T> where
    &'static T: BitXor<U>, 

type Output = <&'static T as BitXor<U>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: U) -> Self::Output

Performs the ^ operation.

impl<T: 'static, U> Shl<U> for Ref<T> where
    &'static T: Shl<U>, 

type Output = <&'static T as Shl<U>>::Output

The resulting type after applying the << operator.

fn shl(self, rhs: U) -> Self::Output

Performs the << operation.

impl<T: 'static, U> Shr<U> for Ref<T> where
    &'static T: Shr<U>, 

type Output = <&'static T as Shr<U>>::Output

The resulting type after applying the >> operator.

fn shr(self, rhs: U) -> Self::Output

Performs the >> operation.