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Diffstat (limited to 'src/libcore/default.rs')
| -rw-r--r-- | src/libcore/default.rs | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/libcore/default.rs b/src/libcore/default.rs index 06402a05d26..9a8d65cd4e0 100644 --- a/src/libcore/default.rs +++ b/src/libcore/default.rs @@ -115,6 +115,50 @@ pub trait Default: Sized { fn default() -> Self; } +/// Return the default value of a type according to the `Default` trait. +/// +/// The type to return is inferred from context; this is equivalent to +/// `Default::default()` but shorter to type. +/// +/// For example: +/// ``` +/// #![feature(default_free_fn)] +/// +/// use std::default::default; +/// +/// #[derive(Default)] +/// struct AppConfig { +/// foo: FooConfig, +/// bar: BarConfig, +/// } +/// +/// #[derive(Default)] +/// struct FooConfig { +/// foo: i32, +/// } +/// +/// #[derive(Default)] +/// struct BarConfig { +/// bar: f32, +/// baz: u8, +/// } +/// +/// fn main() { +/// let options = AppConfig { +/// foo: default(), +/// bar: BarConfig { +/// bar: 10.1, +/// ..default() +/// }, +/// }; +/// } +/// ``` +#[unstable(feature = "default_free_fn", issue = "73014")] +#[inline] +pub fn default<T: Default>() -> T { + Default::default() +} + /// Derive macro generating an impl of the trait `Default`. #[rustc_builtin_macro] #[stable(feature = "builtin_macro_prelude", since = "1.38.0")] |
