Trait core::fmt::Debug
[−]
[src]
pub trait Debug {
fn fmt(&self, &mut Formatter) -> Result;
}Format trait for the ? character.
Debug should format the output in a programmer-facing, debugging context.
Generally speaking, you should just derive a Debug implementation.
When used with the alternate format specifier #?, the output is pretty-printed.
For more information on formatters, see the module-level documentation.
This trait can be used with #[derive].
Examples
Deriving an implementation:
fn main() { #[derive(Debug)] struct Point { x: i32, y: i32, } let origin = Point { x: 0, y: 0 }; println!("The origin is: {:?}", origin); }#[derive(Debug)] struct Point { x: i32, y: i32, } let origin = Point { x: 0, y: 0 }; println!("The origin is: {:?}", origin);
Manually implementing:
fn main() { use std::fmt; struct Point { x: i32, y: i32, } impl fmt::Debug for Point { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "Point {{ x: {}, y: {} }}", self.x, self.y) } } let origin = Point { x: 0, y: 0 }; println!("The origin is: {:?}", origin); }use std::fmt; struct Point { x: i32, y: i32, } impl fmt::Debug for Point { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "Point {{ x: {}, y: {} }}", self.x, self.y) } } let origin = Point { x: 0, y: 0 }; println!("The origin is: {:?}", origin);
This outputs:
The origin is: Point { x: 0, y: 0 }
There are a number of debug_* methods on Formatter to help you with manual
implementations, such as debug_struct.
Debug implementations using either derive or the debug builder API
on Formatter support pretty printing using the alternate flag: {:#?}.
Pretty printing with #?:
#[derive(Debug)] struct Point { x: i32, y: i32, } let origin = Point { x: 0, y: 0 }; println!("The origin is: {:#?}", origin);
This outputs:
The origin is: Point {
x: 0,
y: 0
}
Required Methods
Implementors
impl Debug for Decodedimpl Debug for FullDecodedimpl<'a> Debug for Part<'a>impl Debug for Signimpl Debug for Unpackedimpl Debug for Signimpl<'a> Debug for Decimal<'a>impl<'a> Debug for ParseResult<'a>impl Debug for ParseFloatErrorimpl Debug for FloatErrorKindimpl Debug for Big8x3impl Debug for Big32x40impl Debug for Fpimpl<T: Debug> Debug for Wrapping<T>impl Debug for FpCategoryimpl Debug for ParseIntErrorimpl<T: Debug + Zeroable> Debug for NonZero<T>impl<Ret> Debug for fn() -> Retimpl<Ret> Debug for extern "C" fn() -> Retimpl<Ret> Debug for unsafe fn() -> Retimpl<Ret> Debug for unsafe extern "C" fn() -> Retimpl<Ret, A> Debug for fn(A) -> Retimpl<Ret, A> Debug for extern "C" fn(A) -> Retimpl<Ret, A> Debug for unsafe fn(A) -> Retimpl<Ret, A> Debug for unsafe extern "C" fn(A) -> Retimpl<Ret, A, B> Debug for fn(A, B) -> Retimpl<Ret, A, B> Debug for extern "C" fn(A, B) -> Retimpl<Ret, A, B> Debug for unsafe fn(A, B) -> Retimpl<Ret, A, B> Debug for unsafe extern "C" fn(A, B) -> Retimpl<Ret, A, B, C> Debug for fn(A, B, C) -> Retimpl<Ret, A, B, C> Debug for extern "C" fn(A, B, C) -> Retimpl<Ret, A, B, C> Debug for unsafe fn(A, B, C) -> Retimpl<Ret, A, B, C> Debug for unsafe extern "C" fn(A, B, C) -> Retimpl<Ret, A, B, C, D> Debug for fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D> Debug for extern "C" fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D> Debug for unsafe fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D> Debug for unsafe extern "C" fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D, E> Debug for fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E> Debug for extern "C" fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E> Debug for unsafe fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E> Debug for unsafe extern "C" fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E, F> Debug for fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B, C, D, E, F> Debug for extern "C" fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B, C, D, E, F> Debug for unsafe fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B, C, D, E, F> Debug for unsafe extern "C" fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B, C, D, E, F, G> Debug for fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E, F, G> Debug for extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E, F, G> Debug for unsafe fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E, F, G> Debug for unsafe extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Debug for fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Debug for extern "C" fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Debug for unsafe fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Debug for unsafe extern "C" fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Debug for fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Debug for extern "C" fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Debug for unsafe fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Debug for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Debug for fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Debug for extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Debug for unsafe fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Debug for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Debug for fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Debug for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Debug for unsafe fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Debug for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Debug for fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Debug for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Debug for unsafe fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Debug for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl Debug for RangeFullimpl<Idx: Debug> Debug for Range<Idx>impl<Idx: Debug> Debug for RangeFrom<Idx>impl<Idx: Debug> Debug for RangeTo<Idx>impl<Idx: Debug> Debug for RangeInclusive<Idx>impl<Idx: Debug> Debug for RangeToInclusive<Idx>impl Debug for Orderingimpl Debug for Anyimpl Debug for Any + Sendimpl Debug for TypeIdimpl<T: Debug> Debug for [T; 0]impl<T: Debug> Debug for [T; 1]impl<T: Debug> Debug for [T; 2]impl<T: Debug> Debug for [T; 3]impl<T: Debug> Debug for [T; 4]impl<T: Debug> Debug for [T; 5]impl<T: Debug> Debug for [T; 6]impl<T: Debug> Debug for [T; 7]impl<T: Debug> Debug for [T; 8]impl<T: Debug> Debug for [T; 9]impl<T: Debug> Debug for [T; 10]impl<T: Debug> Debug for [T; 11]impl<T: Debug> Debug for [T; 12]impl<T: Debug> Debug for [T; 13]impl<T: Debug> Debug for [T; 14]impl<T: Debug> Debug for [T; 15]impl<T: Debug> Debug for [T; 16]impl<T: Debug> Debug for [T; 17]impl<T: Debug> Debug for [T; 18]impl<T: Debug> Debug for [T; 19]impl<T: Debug> Debug for [T; 20]impl<T: Debug> Debug for [T; 21]impl<T: Debug> Debug for [T; 22]impl<T: Debug> Debug for [T; 23]impl<T: Debug> Debug for [T; 24]impl<T: Debug> Debug for [T; 25]impl<T: Debug> Debug for [T; 26]impl<T: Debug> Debug for [T; 27]impl<T: Debug> Debug for [T; 28]impl<T: Debug> Debug for [T; 29]impl<T: Debug> Debug for [T; 30]impl<T: Debug> Debug for [T; 31]impl<T: Debug> Debug for [T; 32]impl Debug for Orderingimpl Debug for AtomicUsizeimpl Debug for AtomicIsizeimpl Debug for AtomicBoolimpl<T> Debug for AtomicPtr<T>impl Debug for BorrowStateimpl Debug for EscapeUnicodeimpl Debug for EscapeDefaultimpl Debug for EncodeUtf8impl Debug for EncodeUtf16impl<T: Debug> Debug for Rev<T>impl<I: Debug> Debug for Cloned<I>impl<I: Debug> Debug for Cycle<I>impl<A: Debug, B: Debug> Debug for Chain<A, B>impl<A: Debug, B: Debug> Debug for Zip<A, B>impl<I: Debug, F> Debug for Map<I, F>impl<I: Debug, P> Debug for Filter<I, P>impl<I: Debug, F> Debug for FilterMap<I, F>impl<I: Debug> Debug for Enumerate<I>impl<I: Debug + Iterator> Debug for Peekable<I> where I::Item: Debugimpl<I: Debug, P> Debug for SkipWhile<I, P>impl<I: Debug, P> Debug for TakeWhile<I, P>impl<I: Debug> Debug for Skip<I>impl<I: Debug> Debug for Take<I>impl<I: Debug, St: Debug, F> Debug for Scan<I, St, F>impl<I: Debug, U: IntoIterator, F> Debug for FlatMap<I, U, F> where U::IntoIter: Debugimpl<I: Debug> Debug for Fuse<I>impl<I: Debug, F> Debug for Inspect<I, F>impl<A: Debug, R: Debug> Debug for StepBy<A, R>impl<A: Debug> Debug for Repeat<A>impl<T> Debug for Empty<T>impl<T: Debug> Debug for Once<T>impl<T: Debug> Debug for Option<T>impl<'a, A: Debug + 'a> Debug for Iter<'a, A>impl<'a, A: Debug + 'a> Debug for IterMut<'a, A>impl<A: Debug> Debug for IntoIter<A>impl<T: Debug, E: Debug> Debug for Result<T, E>impl<'a, T: Debug + 'a> Debug for Iter<'a, T>impl<'a, T: Debug + 'a> Debug for IterMut<'a, T>impl<T: Debug> Debug for IntoIter<T>impl<'a, T: 'a + Debug> Debug for Iter<'a, T>impl<'a, T: 'a + Debug> Debug for IterMut<'a, T>impl<'a, T: 'a + Debug, P> Debug for Split<'a, T, P> where P: FnMut(&T) -> boolimpl<'a, T: 'a + Debug, P> Debug for SplitMut<'a, T, P> where P: FnMut(&T) -> boolimpl<'a, T: 'a + Debug, P> Debug for SplitN<'a, T, P> where P: FnMut(&T) -> boolimpl<'a, T: 'a + Debug, P> Debug for RSplitN<'a, T, P> where P: FnMut(&T) -> boolimpl<'a, T: 'a + Debug, P> Debug for SplitNMut<'a, T, P> where P: FnMut(&T) -> boolimpl<'a, T: 'a + Debug, P> Debug for RSplitNMut<'a, T, P> where P: FnMut(&T) -> boolimpl<'a, T: Debug + 'a> Debug for Windows<'a, T>impl<'a, T: Debug + 'a> Debug for Chunks<'a, T>impl<'a, T: Debug + 'a> Debug for ChunksMut<'a, T>impl Debug for SearchStepimpl<'a> Debug for CharSearcher<'a>impl<'a, 'b> Debug for CharSliceSearcher<'a, 'b>impl<'a, F> Debug for CharPredicateSearcher<'a, F> where F: FnMut(char) -> boolimpl<'a, 'b> Debug for StrSearcher<'a, 'b>impl Debug for ParseBoolErrorimpl Debug for Utf8Errorimpl<'a> Debug for Chars<'a>impl<'a> Debug for CharIndices<'a>impl<'a> Debug for Bytes<'a>impl<'a, P: Pattern<'a>> Debug for Split<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for RSplit<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for SplitTerminator<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for RSplitTerminator<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for SplitN<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for RSplitN<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for MatchIndices<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for RMatchIndices<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for Matches<'a, P> where P::Searcher: Debugimpl<'a, P: Pattern<'a>> Debug for RMatches<'a, P> where P::Searcher: Debugimpl<'a> Debug for Lines<'a>impl<'a> Debug for LinesAny<'a>impl Debug for CharRangeimpl Debug for SipHasherimpl<H> Debug for BuildHasherDefault<H>impl Debug for isizeimpl Debug for usizeimpl Debug for i8impl Debug for u8impl Debug for i16impl Debug for u16impl Debug for i32impl Debug for u32impl Debug for i64impl Debug for u64impl Debug for Alignmentimpl Debug for Errorimpl<'a> Debug for Arguments<'a>impl<'a, T: ?Sized + Debug> Debug for &'a Timpl<'a, T: ?Sized + Debug> Debug for &'a mut Timpl Debug for boolimpl Debug for strimpl Debug for charimpl Debug for f32impl Debug for f64impl<T> Debug for *const Timpl<T> Debug for *mut Timpl<T0: Debug, T1: Debug, T2: Debug, T3: Debug, T4: Debug, T5: Debug, T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)impl<T1: Debug, T2: Debug, T3: Debug, T4: Debug, T5: Debug, T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)impl<T2: Debug, T3: Debug, T4: Debug, T5: Debug, T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)impl<T3: Debug, T4: Debug, T5: Debug, T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T3, T4, T5, T6, T7, T8, T9, T10, T11)impl<T4: Debug, T5: Debug, T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T4, T5, T6, T7, T8, T9, T10, T11)impl<T5: Debug, T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T5, T6, T7, T8, T9, T10, T11)impl<T6: Debug, T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T6, T7, T8, T9, T10, T11)impl<T7: Debug, T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T7, T8, T9, T10, T11)impl<T8: Debug, T9: Debug, T10: Debug, T11: Debug> Debug for (T8, T9, T10, T11)impl<T9: Debug, T10: Debug, T11: Debug> Debug for (T9, T10, T11)impl<T10: Debug, T11: Debug> Debug for (T10, T11)impl<T11: Debug> Debug for (T11,)impl<T: Debug> Debug for [T]impl Debug for ()impl<T: ?Sized> Debug for PhantomData<T>impl<T: Copy + Debug> Debug for Cell<T>impl<T: ?Sized + Debug> Debug for RefCell<T>impl<'b, T: ?Sized + Debug> Debug for Ref<'b, T>impl<'b, T: ?Sized + Debug> Debug for RefMut<'b, T>impl<T: ?Sized + Debug> Debug for UnsafeCell<T>