# 1.2.0[−][src]Struct alloc::fmt::DebugStruct

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

A struct to help with `fmt::Debug` implementations.

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

This can be constructed by the `Formatter::debug_struct` method.

# Examples

    use std::fmt;

    struct Foo {
        bar: i32,
        baz: String,
    }

    impl fmt::Debug for Foo {
        fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
            fmt.debug_struct("Foo")
               .field("bar", &self.bar)
               .field("baz", &self.baz)
               .finish()
        }
    }

    // prints "Foo { bar: 10, baz: "Hello World" }"
    println!("{:?}", Foo { bar: 10, baz: "Hello World".to_string() });

## Methods

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

#### `pub fn field(
&mut self,
name: &str,
value: &dyn Debug
) -> &mut DebugStruct<'a, 'b>`[src]

Adds a new field to the generated struct output.

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

Finishes output and returns any error encountered.

## Auto Trait Implementations

### `impl<'a, 'b> !Send for DebugStruct<'a, 'b>`

### `impl<'a, 'b> !Sync for DebugStruct<'a, 'b>`

## Blanket Implementations

### `impl<T> From for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> TryFrom for T where
T: From<U>,` [src]

#### `type Error = !`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

### `impl<T, U> TryInto for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

### `impl<T, U> Into for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T> Borrow for T where
T: ?Sized,` [src]

#### `fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut for T where
T: ?Sized,` [src]

#### `fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn get_type_id(&self) -> TypeId`[src]

🔬 This is a nightly-only experimental API. (`get_type_id` #27745)

this method will likely be replaced by an associated static

Gets the `TypeId` of `self`. Read more

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