pub struct DebugSet<'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 set of items as a part
of your Debug::fmt
implementation.
This can be constructed by the Formatter::debug_set
method.
Examples
use std::fmt;
struct Foo(Vec<i32>);
impl fmt::Debug for Foo {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_set().entries(self.0.iter()).finish()
}
}
assert_eq!(
format!("{:?}", Foo(vec![10, 11])),
"{10, 11}",
);
Implementations§
source§impl<'a, 'b> DebugSet<'a, 'b>where
'b: 'a,
impl<'a, 'b> DebugSet<'a, 'b>where 'b: 'a,
sourcepub fn entry(&mut self, entry: &dyn Debug) -> &mut DebugSet<'a, 'b>
pub fn entry(&mut self, entry: &dyn Debug) -> &mut DebugSet<'a, 'b>
Adds a new entry to the set output.
Examples
use std::fmt;
struct Foo(Vec<i32>, Vec<u32>);
impl fmt::Debug for Foo {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_set()
.entry(&self.0) // Adds the first "entry".
.entry(&self.1) // Adds the second "entry".
.finish()
}
}
assert_eq!(
format!("{:?}", Foo(vec![10, 11], vec![12, 13])),
"{[10, 11], [12, 13]}",
);
sourcepub fn entries<D, I>(&mut self, entries: I) -> &mut DebugSet<'a, 'b>where
D: Debug,
I: IntoIterator<Item = D>,
pub fn entries<D, I>(&mut self, entries: I) -> &mut DebugSet<'a, 'b>where D: Debug, I: IntoIterator<Item = D>,
Adds the contents of an iterator of entries to the set output.
Examples
use std::fmt;
struct Foo(Vec<i32>, Vec<u32>);
impl fmt::Debug for Foo {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_set()
.entries(self.0.iter()) // Adds the first "entry".
.entries(self.1.iter()) // Adds the second "entry".
.finish()
}
}
assert_eq!(
format!("{:?}", Foo(vec![10, 11], vec![12, 13])),
"{10, 11, 12, 13}",
);
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 Foo(Vec<i32>);
impl fmt::Debug for Foo {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_set()
.entries(self.0.iter())
.finish() // Ends the struct formatting.
}
}
assert_eq!(
format!("{:?}", Foo(vec![10, 11])),
"{10, 11}",
);