p formatting.

ThePointer trait should format its output as a memory location. This is commonly presentedas hexadecimal. For more information on formatters, seethe 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 representedin 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 locationsfor different purposes.

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

§Examples

Basic usage with&i32:

letx =&42;letaddress =format!("{x:p}");// this produces something like '0x7f06092ac6d0'

ImplementingPointer on a type:

usestd::fmt;structLength(i32);implfmt::PointerforLength {fnfmt(&self, f:&mutfmt::Formatter<'_>) -> fmt::Result {// use `as` to convert to a `*const T`, which implements Pointer, which we can useletptr =selfas*constSelf;        fmt::Pointer::fmt(&ptr, f)    }}letl = Length(42);println!("l is in memory here: {l:p}");letl_ptr =format!("{l:018p}");assert_eq!(l_ptr.len(),18);assert_eq!(&l_ptr[..2],"0x");