Trait std::fmt::Pointer
p 格式。
Pointer trait 应该将其输出格式化为存储位置。 通常以十六进制表示。
rust
pub trait Pointer {
// Required method
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}&i32 的基本用法：
rust
let x = &42;
let address = format!("{x:p}"); // 这会产生类似 '0x7f06092ac6d0' 的东西在类型上实现 Pointer：
rust
use std::fmt;
struct Length(i32);
impl fmt::Pointer for Length {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// 使用 `as` 转换为 `*const T`，该 `*const T` 实现了 Pointer，我们可以使用它
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
fmt
使用给定的格式化程序格式化该值。
rust
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>Implementors
impl<F> Pointer for F
rust
impl<F> Pointer for F
where
F: FnPtr,impl<P> Pointer for Pin<P>
rust
impl<P> Pointer for Pin<P>
where
P: Pointer,impl<T> Pointer for *const T
rust
impl<T> Pointer for *const T
where
T: ?Sized,impl<T> Pointer for *mut T
rust
impl<T> Pointer for *mut T
where
T: ?Sized,impl<T> Pointer for &T
rust
impl<T> Pointer for &T
where
T: ?Sized,impl<T> Pointer for &mut T
rust
impl<T> Pointer for &mut T
where
T: ?Sized,impl<T> Pointer for NonNull<T>
rust
impl<T> Pointer for NonNull<T>
where
T: ?Sized,impl<T> Pointer for Rc<T>
rust
impl<T> Pointer for Rc<T>
where
T: ?Sized,impl<T> Pointer for AtomicPtr<T>
impl<T> Pointer for Arc<T>
rust
impl<T> Pointer for Arc<T>
where
T: ?Sized,impl<T, A> Pointer for Box<T, A>
rust
impl<T, A> Pointer for Box<T, A>
where
A: Allocator,
T: ?Sized,