Struct core::fmt::DebugSet  1.2.0[−][src]
pub struct DebugSet<'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 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
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]}",
);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 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}",
);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}",
);