[−][src]Trait const_format::marker_traits::FormatMarker

pub trait FormatMarker {
    type Kind;
    type This: ?Sized;
}

This is supported on crate feature fmt only.

Marker trait for types that implement the const formatting methods.

Implementors

Types that implement this trait are also expected to implement at least one of these inherent methods:

// use const_format::{Error, Format};

const fn const_debug_fmt(&self, &mut Formatter<'_>) -> Result<(), Error>

const fn const_display_fmt(&self, &mut Formatter<'_>) -> Result<(), Error>

Coercions

The Kind and This associated types are used in the IsAFormatMarker marker type to automatically wrap types in PWrapper if they're from the standard library, otherwise leaving them unwrapped.

Examples

Display formatting

This example demonstrates how you can implement display formatting, without using the impl_fmt macro.

#![feature(const_mut_refs)]

use const_format::{
    marker_traits::{FormatMarker, IsNotStdKind},
    Error, Formatter, StrWriter,
    formatc, writec,
};

use std::cmp::Ordering;


struct Compared(u32, Ordering, u32);

// This is what the `impl_fmt` macro implements implicitly for all non-std types
impl FormatMarker for Compared {
    type Kind = IsNotStdKind;
    type This = Self;
}

impl Compared {
    pub const fn const_display_fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
        let op = match self.1 {
            Ordering::Less => "<",
            Ordering::Equal => "==",
            Ordering::Greater => ">",
        };
        writec!(f, "{} {} {}", self.0, op, self.2)
    }
}

const S_0: &str = formatc!("{}", Compared(0, Ordering::Less, 1));
const S_1: &str = formatc!("{}", Compared(1, Ordering::Equal, 1));
const S_2: &str = formatc!("{}", Compared(2, Ordering::Greater, 1));

assert_eq!(S_0, "0 < 1");
assert_eq!(S_1, "1 == 1");
assert_eq!(S_2, "2 > 1");

Debug formatting

These are examples of implementing debug formatting using the impl_fmt macro for:

Associated Types

`type Kind`[src]

What kind of type this is, this can be one of:

IsArrayKind: For slices, and arrays.
IsStdKind: Any other standard library type.
IsNotStdKind: Any type that is not from the standard library.

`type This: ?Sized`[src]

The type after dereferencing, implemented as type This = Self; for all non-reference types

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Implementations on Foreign Types

`impl FormatMarker for Range<usize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for RangeFrom<usize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for RangeTo<usize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for RangeToInclusive<usize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for RangeInclusive<usize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for RangeFull`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<T> FormatMarker for Option<NonNull<T>>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroU8>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroI8>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroU16>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroI16>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroU32>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroI32>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroU64>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroI64>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroU128>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroI128>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroUsize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<NonZeroIsize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<u8>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<i8>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<u16>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<i16>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<u32>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<i32>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<u64>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<i64>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<u128>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<i128>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<usize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<isize>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Option<bool>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<'a> FormatMarker for Option<&'a str>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroU8`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroI8`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroU16`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroI16`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroU32`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroI32`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroU64`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroI64`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroU128`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroI128`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroUsize`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for NonZeroIsize`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<T> FormatMarker for NonNull<T>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<T: ?Sized> FormatMarker for PhantomData<T>`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for PhantomPinned`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for AtomicOrdering`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Ordering`[src]

`type Kind = IsStdKind`

`type This = Self`

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Implementors

`impl FormatMarker for ()`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for Point3`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl FormatMarker for Unit`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl FormatMarker for AsciiStr<'_>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl FormatMarker for bool`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for i8`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for i16`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for i32`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for i64`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for i128`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for isize`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for str`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for u8`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for u16`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for u32`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for u64`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for u128`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl FormatMarker for usize`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<&'a str, Range<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<&'a str, RangeFrom<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<&'a str, RangeFull>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<&'a str, RangeInclusive<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<&'a str, RangeTo<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<&'a str, RangeToInclusive<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<AsciiStr<'a>, Range<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<AsciiStr<'a>, RangeFrom<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<AsciiStr<'a>, RangeFull>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<AsciiStr<'a>, RangeInclusive<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<AsciiStr<'a>, RangeTo<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<'a> FormatMarker for Sliced<AsciiStr<'a>, RangeToInclusive<usize>>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<P> FormatMarker for PWrapper<P>`[src]

`type Kind = IsNotStdKind`

`type This = Self`

`impl<T> FormatMarker for *const T`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<T> FormatMarker for *mut T`[src]

`type Kind = IsStdKind`

`type This = Self`

`impl<T> FormatMarker for [T; 0]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 1]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 2]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 3]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 4]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 5]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 6]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 7]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 8]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 9]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 10]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 11]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 12]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 13]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 14]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 15]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 16]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 17]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 18]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 19]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 20]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 21]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 22]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 23]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 24]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 25]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 26]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 27]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 28]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 29]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 30]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 31]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 32]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 33]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 34]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 35]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 36]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 37]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 38]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 39]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 40]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 41]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 42]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 43]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 44]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 45]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 46]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 47]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 48]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 49]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 50]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 51]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 52]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 53]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 54]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 55]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 56]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 57]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 58]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 59]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 60]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 61]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 62]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T; 63]`[src]

`type Kind = IsArrayKind<T>`

`type This = Self`

`impl<T> FormatMarker for [T]`[src]

`type Kind = IsArrayKind<T>`

`type This = [T]`

`impl<T: ?Sized> FormatMarker for &T where T: FormatMarker,` [src]

`type Kind = T::Kind`

`type This = T::This`

`impl<T: ?Sized> FormatMarker for &mut T where T: FormatMarker,` [src]

`type Kind = T::Kind`

`type This = T::This`

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