core::fmt::DebugMap - Rust
Description: API documentation for the Rust `DebugMap` struct in crate `core`.
Keywords: rust, rustlang, rust-lang, DebugMap

# Struct core::fmt::DebugMap 1.2.0 [−] [src]

    #[must_use]
    pub struct DebugMap<'a, '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)]));Run

## Methods

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

#### `pub fn entry(&mut self, key: &Debug, value: &Debug) -> &mut DebugMap<'a, 'b>`
[src]

Adds a new entry to the map output.

#### `pub fn entries<K, V, I>(&mut self, entries: I) -> &mut DebugMap<'a, 'b> where
K: Debug,
V: Debug,
I: IntoIterator<Item = (K, V)>,`
[src]

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

#### `pub fn finish(&mut self) -> Result`
[src]

Finishes output and returns any error encountered.

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