Struct std::fmt::DebugMap1.2.0[][src]

#[must_use = "must eventually call `finish()` on Debug builders"]
pub struct DebugMap<'a, 'b> where
    'b: 'a, 
{ /* fields omitted */ }

A struct to help with fmt::Debug implementations.

This is useful when you wish to output a formatted map as a part of your Debug::fmt implementation.

This can be constructed by the Formatter::debug_map method.


use std::fmt;

struct Foo(Vec<(String, i32)>);

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_map().entries(self.0.iter().map(|&(ref k, ref v)| (k, v))).finish()

// prints "{"A": 10, "B": 11}"
println!("{:?}", Foo(vec![("A".to_string(), 10), ("B".to_string(), 11)]));Run


impl<'a, 'b> DebugMap<'a, 'b> where
    'b: 'a, 

Adds a new entry to the map output.

Adds the contents of an iterator of entries to the map output.

Finishes output and returns any error encountered.

Auto Trait Implementations

impl<'a, 'b> !Send for DebugMap<'a, 'b>

impl<'a, 'b> !Sync for DebugMap<'a, 'b>