Struct core::fmt::DebugList 1.2.0[−][src]
pub struct DebugList<'a, 'b: 'a> { /* fields omitted */ }
Expand description
A struct to help with fmt::Debug
implementations.
This is useful when you wish to output a formatted list of items as a part
of your Debug::fmt
implementation.
This can be constructed by the Formatter::debug_list
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_list().entries(self.0.iter()).finish() } } assert_eq!( format!("{:?}", Foo(vec![10, 11])), "[10, 11]", );Run
Implementations
Adds a new entry to the list 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_list() .entry(&self.0) // We add the first "entry". .entry(&self.1) // We add the second "entry". .finish() } } assert_eq!( format!("{:?}", Foo(vec![10, 11], vec![12, 13])), "[[10, 11], [12, 13]]", );Run
pub fn entries<D, I>(&mut self, entries: I) -> &mut Self where
D: Debug,
I: IntoIterator<Item = D>,
pub fn entries<D, I>(&mut self, entries: I) -> &mut Self where
D: Debug,
I: IntoIterator<Item = D>,
Adds the contents of an iterator of entries to the list 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_list() .entries(self.0.iter()) .entries(self.1.iter()) .finish() } } assert_eq!( format!("{:?}", Foo(vec![10, 11], vec![12, 13])), "[10, 11, 12, 13]", );Run
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_list() .entries(self.0.iter()) .finish() // Ends the struct formatting. } } assert_eq!( format!("{:?}", Foo(vec![10, 11])), "[10, 11]", );Run