Trait Pointer 

pub trait Pointer {
    // Required method
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}

p formatting.

The Pointer trait should format its output as a memory location. This is commonly presented as hexadecimal. For more information on formatters, see the module-level documentation.

Printing of pointers is not a reliable way to discover how Rust programs are implemented. The act of reading an address changes the program itself, and may change how the data is represented in memory, and may affect which optimizations are applied to the code.

The printed pointer values are not guaranteed to be stable nor unique identifiers of objects. Rust allows moving values to different memory locations, and may reuse the same memory locations for different purposes.

There is no guarantee that the printed value can be converted back to a pointer.

Examples

Basic usage with &i32:

let x = &42;

let address = format!("{x:p}"); // this produces something like '0x7f06092ac6d0'

Implementing Pointer on a type:

use std::fmt;

struct Length(i32);

impl fmt::Pointer for Length {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        // use `as` to convert to a `*const T`, which implements Pointer, which we can use

        let ptr = self as *const Self;
        fmt::Pointer::fmt(&ptr, f)
    }
}

let l = Length(42);

println!("l is in memory here: {l:p}");

let l_ptr = format!("{l:018p}");
assert_eq!(l_ptr.len(), 18);
assert_eq!(&l_ptr[..2], "0x");

Required Methods

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

Formats the value using the given formatter.

Errors

This function should return Err if, and only if, the provided Formatter returns Err. String formatting is considered an infallible operation; this function only returns a Result because writing to the underlying stream might fail and it must provide a way to propagate the fact that an error has occurred back up the stack.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Pointer for AccelerationStructureKHR

impl Pointer for AccelerationStructureNV

impl Pointer for Buffer

impl Pointer for BufferView

impl Pointer for CommandBuffer

impl Pointer for CommandPool

impl Pointer for CuFunctionNVX

impl Pointer for CuModuleNVX

impl Pointer for DebugReportCallbackEXT

impl Pointer for DebugUtilsMessengerEXT

impl Pointer for DeferredOperationKHR

impl Pointer for DescriptorPool

impl Pointer for DescriptorSet

impl Pointer for DescriptorSetLayout

impl Pointer for DescriptorUpdateTemplate

impl Pointer for Device

impl Pointer for DeviceMemory

impl Pointer for DisplayKHR

impl Pointer for DisplayModeKHR

impl Pointer for Event

impl Pointer for Fence

impl Pointer for Framebuffer

impl Pointer for GpaSessionAmd

impl Pointer for Image

impl Pointer for ImageView

impl Pointer for IndirectCommandsLayoutNV

impl Pointer for Instance

impl Pointer for PerformanceConfigurationINTEL

impl Pointer for PhysicalDevice

impl Pointer for Pipeline

impl Pointer for PipelineCache

impl Pointer for PipelineLayout

impl Pointer for PrivateDataSlotEXT

impl Pointer for QueryPool

impl Pointer for Queue

impl Pointer for RenderPass

impl Pointer for Sampler

impl Pointer for SamplerYcbcrConversion

impl Pointer for Semaphore

impl Pointer for ShaderModule

impl Pointer for SurfaceKHR

impl Pointer for SwapchainKHR

impl Pointer for ValidationCacheEXT

impl Pointer for VideoSessionKHR

impl Pointer for VideoSessionParametersKHR

impl<F> Pointer for F

where F: FnPtr,

impl<Ptr> Pointer for Pin<Ptr>

where Ptr: Pointer,

impl<T, A> Pointer for Arc<T, A>

where A: Allocator, T: ?Sized,

impl<T, A> Pointer for Box<T, A>

where A: Allocator, T: ?Sized,

impl<T, A> Pointer for Rc<T, A>

where A: Allocator, T: ?Sized,

impl<T, A> Pointer for UniqueArc<T, A>

where A: Allocator, T: ?Sized,

impl<T, A> Pointer for UniqueRc<T, A>

where A: Allocator, T: ?Sized,

impl<T> Pointer for &T

where T: ?Sized,

impl<T> Pointer for &mut T

where T: ?Sized,

impl<T> Pointer for *const T

where T: ?Sized,

impl<T> Pointer for *mut T

where T: ?Sized,

impl<T> Pointer for core::sync::atomic::Atomic<*mut T>

Available on target_has_atomic_load_store=ptr only.

impl<T> Pointer for crossbeam_epoch::atomic::Atomic<T>

where T: Pointable + ?Sized,

impl<T> Pointer for NonNull<T>

where T: ?Sized,

impl<T> Pointer for Shared<'_, T>

where T: Pointable + ?Sized,