pub struct Ref<T>(/* private fields */);Expand description
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.
Implementations§
Source§impl<T> Ref<T>
impl<T> Ref<T>
Sourcepub unsafe fn new(ptr: Ptr<T>) -> Option<Self>
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.
Sourcepub unsafe fn from_raw(ptr: *const T) -> Option<Self>
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.
Sourcepub unsafe fn from_raw_ref(value: &T) -> Self
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.
Sourcepub unsafe fn from_raw_non_null(ptr: NonNull<T>) -> Self
pub unsafe fn from_raw_non_null(ptr: NonNull<T>) -> Self
Sourcepub fn as_raw_ptr(self) -> *const T
pub fn as_raw_ptr(self) -> *const T
Returns constant raw pointer to the value.
Sourcepub unsafe fn static_upcast<U>(self) -> Ref<U>where
T: StaticUpcast<U>,
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.
Sourcepub unsafe fn static_downcast<U>(self) -> Ref<U>where
T: StaticDowncast<U>,
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.
Sourcepub unsafe fn dynamic_cast<U>(self) -> Option<Ref<U>>where
T: DynamicCast<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.
Sourcepub unsafe fn begin(self) -> <&'static T as Begin>::Outputwhere
&'static T: Begin,
pub unsafe fn begin(self) -> <&'static T as Begin>::Outputwhere
&'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.
Sourcepub unsafe fn end(self) -> <&'static T as End>::Outputwhere
&'static T: End,
pub unsafe fn end(self) -> <&'static T as End>::Outputwhere
&'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.
Sourcepub unsafe fn as_slice<'a, T1>(self) -> &'a [T1]
pub unsafe fn as_slice<'a, T1>(self) -> &'a [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§
Source§impl<'a, T, U> CastFrom<&'a CppBox<U>> for Ref<T>where
U: StaticUpcast<T> + CppDeletable,
impl<'a, T, U> CastFrom<&'a CppBox<U>> for Ref<T>where
U: StaticUpcast<T> + CppDeletable,
Source§impl<T> Deref for Ref<T>
Allows to call member functions of T and its base classes directly on the pointer.
impl<T> Deref for Ref<T>
Allows to call member functions of T and its base classes directly on the pointer.
Source§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,
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,
Source§type Item = <&'static T1 as Indirection>::Output
type Item = <&'static T1 as Indirection>::Output
Source§type IntoIter = CppIterator<T1, T2>
type IntoIter = CppIterator<T1, T2>
Source§impl<T, U> PartialOrd<U> for Ref<T>
impl<T, U> PartialOrd<U> for Ref<T>
impl<T> Copy for Ref<T>
Creates another pointer to the same object.