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

#[must_use]
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.

Examples

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)]));

Methods

impl<'a, 'b> DebugMap<'a, 'b> where
    'b: 'a, 
[src]

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.

Trait Implementations

Auto Trait Implementations

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

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