Trait glib::translate::FromGlibPtrBorrow[−][src]

pub trait FromGlibPtrBorrow<P: Ptr>: Sized {
    unsafe fn from_glib_borrow(_ptr: P) -> Borrowed<Self> { ... }
}

Expand description

Translate from a pointer type by borrowing, without affecting the refcount.

The purpose of this trait is to access values inside callbacks without changing their reference status. The obtained borrow must not be accessed outside of the scope of the callback, and called procedures must not store any references to the underlying data. Safe Rust code must never obtain a mutable Rust reference.

Safety

The implementation of this trait as well as the returned type must satisfy the same constraints together. They must not take ownership of the underlying value, copy it, and should not change its rerefence count. If it does, it must properly release obtained references.

The returned value, when dropped, must leave the underlying value in the same state as before from_glib_borrow was called:

it must not be dropped,
it must be the same type of reference, e.g. still floating.

For more information, refer to module level documentation.

Provided methods

unsafe fn from_glib_borrow(_ptr: P) -> Borrowed<Self>

Safety

See trait level notes on safety

Implementations on Foreign Types

impl<P: Ptr, T: FromGlibPtrBorrow<P>> FromGlibPtrBorrow<P> for Option<T>

unsafe fn from_glib_borrow(ptr: P) -> Borrowed<Option<T>>

Implementors

impl<T: 'static, MM: BoxedMemoryManager<T>> FromGlibPtrBorrow<*mut T> for Boxed<T, MM>

impl<T: 'static, MM: SharedMemoryManager<T>> FromGlibPtrBorrow<*mut T> for Shared<T, MM>

`impl FromGlibPtrBorrow<*mut cairo_t> for Context`

`impl FromGlibPtrBorrow<*mut cairo_device_t> for Device`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for ImageSurface`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for RecordingSurface`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for Surface`

`impl FromGlibPtrBorrow<*mut xcb_connection_t> for XCBConnection`

`impl FromGlibPtrBorrow<*mut xcb_render_pictforminfo_t> for XCBRenderPictFormInfo`

`impl FromGlibPtrBorrow<*mut xcb_screen_t> for XCBScreen`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for XCBSurface`

`impl FromGlibPtrBorrow<*mut xcb_visualtype_t> for XCBVisualType`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for PdfSurface`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for PsSurface`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for SvgSurface`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for QuartzSurface`

`impl FromGlibPtrBorrow<*mut cairo_surface_t> for Win32Surface`