Struct frame_support::dispatch::fmt::DebugStruct
1.2.0 · source · pub struct DebugStruct<'a, 'b>where
'b: 'a,{ /* private fields */ }
Expand description
A struct to help with fmt::Debug
implementations.
This is useful when you wish to output a formatted struct as a part of your
Debug::fmt
implementation.
This can be constructed by the Formatter::debug_struct
method.
Examples
use std::fmt;
struct Foo {
bar: i32,
baz: String,
}
impl fmt::Debug for Foo {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_struct("Foo")
.field("bar", &self.bar)
.field("baz", &self.baz)
.finish()
}
}
assert_eq!(
format!("{:?}", Foo { bar: 10, baz: "Hello World".to_string() }),
"Foo { bar: 10, baz: \"Hello World\" }",
);
Implementations
sourceimpl<'a, 'b> DebugStruct<'a, 'b>where
'b: 'a,
impl<'a, 'b> DebugStruct<'a, 'b>where
'b: 'a,
sourcepub fn field(&mut self, name: &str, value: &dyn Debug) -> &mut DebugStruct<'a, 'b>
pub fn field(&mut self, name: &str, value: &dyn Debug) -> &mut DebugStruct<'a, 'b>
Adds a new field to the generated struct output.
Examples
use std::fmt;
struct Bar {
bar: i32,
another: String,
}
impl fmt::Debug for Bar {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("Bar")
.field("bar", &self.bar) // We add `bar` field.
.field("another", &self.another) // We add `another` field.
// We even add a field which doesn't exist (because why not?).
.field("not_existing_field", &1)
.finish() // We're good to go!
}
}
assert_eq!(
format!("{:?}", Bar { bar: 10, another: "Hello World".to_string() }),
"Bar { bar: 10, another: \"Hello World\", not_existing_field: 1 }",
);
1.53.0 · sourcepub fn finish_non_exhaustive(&mut self) -> Result<(), Error>
pub fn finish_non_exhaustive(&mut self) -> Result<(), Error>
Marks the struct as non-exhaustive, indicating to the reader that there are some other fields that are not shown in the debug representation.
Examples
use std::fmt;
struct Bar {
bar: i32,
hidden: f32,
}
impl fmt::Debug for Bar {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("Bar")
.field("bar", &self.bar)
.finish_non_exhaustive() // Show that some other field(s) exist.
}
}
assert_eq!(
format!("{:?}", Bar { bar: 10, hidden: 1.0 }),
"Bar { bar: 10, .. }",
);
sourcepub fn finish(&mut self) -> Result<(), Error>
pub fn finish(&mut self) -> Result<(), Error>
Finishes output and returns any error encountered.
Examples
use std::fmt;
struct Bar {
bar: i32,
baz: String,
}
impl fmt::Debug for Bar {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("Bar")
.field("bar", &self.bar)
.field("baz", &self.baz)
.finish() // You need to call it to "finish" the
// struct formatting.
}
}
assert_eq!(
format!("{:?}", Bar { bar: 10, baz: "Hello World".to_string() }),
"Bar { bar: 10, baz: \"Hello World\" }",
);
Trait Implementations
sourceimpl<'a, 'b> Visit for DebugStruct<'a, 'b>
impl<'a, 'b> Visit for DebugStruct<'a, 'b>
sourcefn record_debug(&mut self, field: &Field, value: &dyn Debug)
fn record_debug(&mut self, field: &Field, value: &dyn Debug)
Visit a value implementing
fmt::Debug
.sourcefn record_f64(&mut self, field: &Field, value: f64)
fn record_f64(&mut self, field: &Field, value: f64)
Visit a double-precision floating point value.
sourcefn record_i64(&mut self, field: &Field, value: i64)
fn record_i64(&mut self, field: &Field, value: i64)
Visit a signed 64-bit integer value.
sourcefn record_u64(&mut self, field: &Field, value: u64)
fn record_u64(&mut self, field: &Field, value: u64)
Visit an unsigned 64-bit integer value.
sourcefn record_i128(&mut self, field: &Field, value: i128)
fn record_i128(&mut self, field: &Field, value: i128)
Visit a signed 128-bit integer value.
sourcefn record_u128(&mut self, field: &Field, value: u128)
fn record_u128(&mut self, field: &Field, value: u128)
Visit an unsigned 128-bit integer value.
sourcefn record_bool(&mut self, field: &Field, value: bool)
fn record_bool(&mut self, field: &Field, value: bool)
Visit a boolean value.
sourcefn record_str(&mut self, field: &Field, value: &str)
fn record_str(&mut self, field: &Field, value: &str)
Visit a string value.
sourcefn record_error(&mut self, field: &Field, value: &(dyn Error + 'static))
fn record_error(&mut self, field: &Field, value: &(dyn Error + 'static))
Records a type implementing
Error
. Read moreAuto Trait Implementations
impl<'a, 'b> !RefUnwindSafe for DebugStruct<'a, 'b>
impl<'a, 'b> !Send for DebugStruct<'a, 'b>
impl<'a, 'b> !Sync for DebugStruct<'a, 'b>
impl<'a, 'b> Unpin for DebugStruct<'a, 'b>where
'b: 'a,
impl<'a, 'b> !UnwindSafe for DebugStruct<'a, 'b>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> CheckedConversion for T
impl<T> CheckedConversion for T
sourcefn checked_from<T>(t: T) -> Option<Self>where
Self: TryFrom<T>,
fn checked_from<T>(t: T) -> Option<Self>where
Self: TryFrom<T>,
sourcefn checked_into<T>(self) -> Option<T>where
Self: TryInto<T>,
fn checked_into<T>(self) -> Option<T>where
Self: TryInto<T>,
impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
Convert
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
. Read morefn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Convert
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read morefn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read morefn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s. Read moresourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T, Outer> IsWrappedBy<Outer> for Twhere
Outer: AsRef<T> + AsMut<T> + From<T>,
T: From<Outer>,
impl<T, Outer> IsWrappedBy<Outer> for Twhere
Outer: AsRef<T> + AsMut<T> + From<T>,
T: From<Outer>,
impl<T> Pointable for T
impl<T> Pointable for T
sourceimpl<T> SaturatedConversion for T
impl<T> SaturatedConversion for T
sourcefn saturated_from<T>(t: T) -> Selfwhere
Self: UniqueSaturatedFrom<T>,
fn saturated_from<T>(t: T) -> Selfwhere
Self: UniqueSaturatedFrom<T>,
sourcefn saturated_into<T>(self) -> Twhere
Self: UniqueSaturatedInto<T>,
fn saturated_into<T>(self) -> Twhere
Self: UniqueSaturatedInto<T>,
Consume self to return an equivalent value of
T
. Read moresourceimpl<S, T> UncheckedInto<T> for Swhere
T: UncheckedFrom<S>,
impl<S, T> UncheckedInto<T> for Swhere
T: UncheckedFrom<S>,
sourcefn unchecked_into(self) -> T
fn unchecked_into(self) -> T
The counterpart to
unchecked_from
.sourceimpl<T, S> UniqueSaturatedInto<T> for Swhere
T: Bounded,
S: TryInto<T>,
impl<T, S> UniqueSaturatedInto<T> for Swhere
T: Bounded,
S: TryInto<T>,
sourcefn unique_saturated_into(self) -> T
fn unique_saturated_into(self) -> T
Consume self to return an equivalent value of
T
.