1 // SPDX-License-Identifier: GPL-2.0 2 3 //! Formatting utilities. 4 //! 5 //! This module is intended to be used in place of `core::fmt` in kernel code. 6 7 pub use core::fmt::{Arguments, Debug, Error, Formatter, Result, Write}; 8 9 /// Internal adapter used to route allow implementations of formatting traits for foreign types. 10 /// 11 /// It is inserted automatically by the [`fmt!`] macro and is not meant to be used directly. 12 /// 13 /// [`fmt!`]: crate::prelude::fmt! 14 #[doc(hidden)] 15 pub struct Adapter<T>(pub T); 16 17 macro_rules! impl_fmt_adapter_forward { 18 ($($trait:ident),* $(,)?) => { 19 $( 20 impl<T: $trait> $trait for Adapter<T> { 21 fn fmt(&self, f: &mut Formatter<'_>) -> Result { 22 let Self(t) = self; 23 $trait::fmt(t, f) 24 } 25 } 26 )* 27 }; 28 } 29 30 use core::fmt::{Binary, LowerExp, LowerHex, Octal, Pointer, UpperExp, UpperHex}; 31 impl_fmt_adapter_forward!(Debug, LowerHex, UpperHex, Octal, Binary, Pointer, LowerExp, UpperExp); 32 33 /// A copy of [`core::fmt::Display`] that allows us to implement it for foreign types. 34 /// 35 /// Types should implement this trait rather than [`core::fmt::Display`]. Together with the 36 /// [`Adapter`] type and [`fmt!`] macro, it allows for formatting foreign types (e.g. types from 37 /// core) which do not implement [`core::fmt::Display`] directly. 38 /// 39 /// [`fmt!`]: crate::prelude::fmt! 40 pub trait Display { 41 /// Same as [`core::fmt::Display::fmt`]. 42 fn fmt(&self, f: &mut Formatter<'_>) -> Result; 43 } 44 45 impl<T: ?Sized + Display> Display for &T { 46 fn fmt(&self, f: &mut Formatter<'_>) -> Result { 47 Display::fmt(*self, f) 48 } 49 } 50 51 impl<T: ?Sized + Display> core::fmt::Display for Adapter<&T> { 52 fn fmt(&self, f: &mut Formatter<'_>) -> Result { 53 let Self(t) = self; 54 Display::fmt(t, f) 55 } 56 } 57 58 macro_rules! impl_display_forward { 59 ($( 60 $( { $($generics:tt)* } )? $ty:ty $( { where $($where:tt)* } )? 61 ),* $(,)?) => { 62 $( 63 impl$($($generics)*)? Display for $ty $(where $($where)*)? { 64 fn fmt(&self, f: &mut Formatter<'_>) -> Result { 65 core::fmt::Display::fmt(self, f) 66 } 67 } 68 )* 69 }; 70 } 71 72 impl_display_forward!( 73 bool, 74 char, 75 core::panic::PanicInfo<'_>, 76 Arguments<'_>, 77 i128, 78 i16, 79 i32, 80 i64, 81 i8, 82 isize, 83 str, 84 u128, 85 u16, 86 u32, 87 u64, 88 u8, 89 usize, 90 {<T: ?Sized>} crate::sync::Arc<T> {where crate::sync::Arc<T>: core::fmt::Display}, 91 {<T: ?Sized>} crate::sync::UniqueArc<T> {where crate::sync::UniqueArc<T>: core::fmt::Display}, 92 ); 93