diff options
Diffstat (limited to 'library/core/src/ops/function.rs')
| -rw-r--r-- | library/core/src/ops/function.rs | 319 |
1 files changed, 0 insertions, 319 deletions
diff --git a/library/core/src/ops/function.rs b/library/core/src/ops/function.rs index 127b047db..b7e1aee9d 100644 --- a/library/core/src/ops/function.rs +++ b/library/core/src/ops/function.rs @@ -1,4 +1,3 @@ -#[cfg(not(bootstrap))] use crate::marker::Tuple; /// The version of the call operator that takes an immutable receiver. @@ -54,87 +53,6 @@ use crate::marker::Tuple; /// let double = |x| x * 2; /// assert_eq!(call_with_one(double), 2); /// ``` -#[cfg(bootstrap)] -#[lang = "fn"] -#[stable(feature = "rust1", since = "1.0.0")] -#[rustc_paren_sugar] -#[rustc_on_unimplemented( - on( - Args = "()", - note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" - ), - on( - _Self = "unsafe fn", - note = "unsafe function cannot be called generically without an unsafe block", - // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string - label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" - ), - message = "expected a `{Fn}<{Args}>` closure, found `{Self}`", - label = "expected an `Fn<{Args}>` closure, found `{Self}`" -)] -#[fundamental] // so that regex can rely that `&str: !FnMut` -#[must_use = "closures are lazy and do nothing unless called"] -#[const_trait] -pub trait Fn<Args>: FnMut<Args> { - /// Performs the call operation. - #[unstable(feature = "fn_traits", issue = "29625")] - extern "rust-call" fn call(&self, args: Args) -> Self::Output; -} - -/// The version of the call operator that takes an immutable receiver. -/// -/// Instances of `Fn` can be called repeatedly without mutating state. -/// -/// *This trait (`Fn`) is not to be confused with [function pointers] -/// (`fn`).* -/// -/// `Fn` is implemented automatically by closures which only take immutable -/// references to captured variables or don't capture anything at all, as well -/// as (safe) [function pointers] (with some caveats, see their documentation -/// for more details). Additionally, for any type `F` that implements `Fn`, `&F` -/// implements `Fn`, too. -/// -/// Since both [`FnMut`] and [`FnOnce`] are supertraits of `Fn`, any -/// instance of `Fn` can be used as a parameter where a [`FnMut`] or [`FnOnce`] -/// is expected. -/// -/// Use `Fn` as a bound when you want to accept a parameter of function-like -/// type and need to call it repeatedly and without mutating state (e.g., when -/// calling it concurrently). If you do not need such strict requirements, use -/// [`FnMut`] or [`FnOnce`] as bounds. -/// -/// See the [chapter on closures in *The Rust Programming Language*][book] for -/// some more information on this topic. -/// -/// Also of note is the special syntax for `Fn` traits (e.g. -/// `Fn(usize, bool) -> usize`). Those interested in the technical details of -/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. -/// -/// [book]: ../../book/ch13-01-closures.html -/// [function pointers]: fn -/// [nomicon]: ../../nomicon/hrtb.html -/// -/// # Examples -/// -/// ## Calling a closure -/// -/// ``` -/// let square = |x| x * x; -/// assert_eq!(square(5), 25); -/// ``` -/// -/// ## Using a `Fn` parameter -/// -/// ``` -/// fn call_with_one<F>(func: F) -> usize -/// where F: Fn(usize) -> usize { -/// func(1) -/// } -/// -/// let double = |x| x * 2; -/// assert_eq!(call_with_one(double), 2); -/// ``` -#[cfg(not(bootstrap))] #[lang = "fn"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_paren_sugar] @@ -222,95 +140,6 @@ pub trait Fn<Args: Tuple>: FnMut<Args> { /// /// assert_eq!(x, 5); /// ``` -#[cfg(bootstrap)] -#[lang = "fn_mut"] -#[stable(feature = "rust1", since = "1.0.0")] -#[rustc_paren_sugar] -#[rustc_on_unimplemented( - on( - Args = "()", - note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" - ), - on( - _Self = "unsafe fn", - note = "unsafe function cannot be called generically without an unsafe block", - // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string - label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" - ), - message = "expected a `{FnMut}<{Args}>` closure, found `{Self}`", - label = "expected an `FnMut<{Args}>` closure, found `{Self}`" -)] -#[fundamental] // so that regex can rely that `&str: !FnMut` -#[must_use = "closures are lazy and do nothing unless called"] -#[const_trait] -pub trait FnMut<Args>: FnOnce<Args> { - /// Performs the call operation. - #[unstable(feature = "fn_traits", issue = "29625")] - extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output; -} - -/// The version of the call operator that takes a mutable receiver. -/// -/// Instances of `FnMut` can be called repeatedly and may mutate state. -/// -/// `FnMut` is implemented automatically by closures which take mutable -/// references to captured variables, as well as all types that implement -/// [`Fn`], e.g., (safe) [function pointers] (since `FnMut` is a supertrait of -/// [`Fn`]). Additionally, for any type `F` that implements `FnMut`, `&mut F` -/// implements `FnMut`, too. -/// -/// Since [`FnOnce`] is a supertrait of `FnMut`, any instance of `FnMut` can be -/// used where a [`FnOnce`] is expected, and since [`Fn`] is a subtrait of -/// `FnMut`, any instance of [`Fn`] can be used where `FnMut` is expected. -/// -/// Use `FnMut` as a bound when you want to accept a parameter of function-like -/// type and need to call it repeatedly, while allowing it to mutate state. -/// If you don't want the parameter to mutate state, use [`Fn`] as a -/// bound; if you don't need to call it repeatedly, use [`FnOnce`]. -/// -/// See the [chapter on closures in *The Rust Programming Language*][book] for -/// some more information on this topic. -/// -/// Also of note is the special syntax for `Fn` traits (e.g. -/// `Fn(usize, bool) -> usize`). Those interested in the technical details of -/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. -/// -/// [book]: ../../book/ch13-01-closures.html -/// [function pointers]: fn -/// [nomicon]: ../../nomicon/hrtb.html -/// -/// # Examples -/// -/// ## Calling a mutably capturing closure -/// -/// ``` -/// let mut x = 5; -/// { -/// let mut square_x = || x *= x; -/// square_x(); -/// } -/// assert_eq!(x, 25); -/// ``` -/// -/// ## Using a `FnMut` parameter -/// -/// ``` -/// fn do_twice<F>(mut func: F) -/// where F: FnMut() -/// { -/// func(); -/// func(); -/// } -/// -/// let mut x: usize = 1; -/// { -/// let add_two_to_x = || x += 2; -/// do_twice(add_two_to_x); -/// } -/// -/// assert_eq!(x, 5); -/// ``` -#[cfg(not(bootstrap))] #[lang = "fn_mut"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_paren_sugar] @@ -390,92 +219,6 @@ pub trait FnMut<Args: Tuple>: FnOnce<Args> { /// /// // `consume_and_return_x` can no longer be invoked at this point /// ``` -#[cfg(bootstrap)] -#[lang = "fn_once"] -#[stable(feature = "rust1", since = "1.0.0")] -#[rustc_paren_sugar] -#[rustc_on_unimplemented( - on( - Args = "()", - note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" - ), - on( - _Self = "unsafe fn", - note = "unsafe function cannot be called generically without an unsafe block", - // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string - label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" - ), - message = "expected a `{FnOnce}<{Args}>` closure, found `{Self}`", - label = "expected an `FnOnce<{Args}>` closure, found `{Self}`" -)] -#[fundamental] // so that regex can rely that `&str: !FnMut` -#[must_use = "closures are lazy and do nothing unless called"] -#[const_trait] -pub trait FnOnce<Args> { - /// The returned type after the call operator is used. - #[lang = "fn_once_output"] - #[stable(feature = "fn_once_output", since = "1.12.0")] - type Output; - - /// Performs the call operation. - #[unstable(feature = "fn_traits", issue = "29625")] - extern "rust-call" fn call_once(self, args: Args) -> Self::Output; -} - -/// The version of the call operator that takes a by-value receiver. -/// -/// Instances of `FnOnce` can be called, but might not be callable multiple -/// times. Because of this, if the only thing known about a type is that it -/// implements `FnOnce`, it can only be called once. -/// -/// `FnOnce` is implemented automatically by closures that might consume captured -/// variables, as well as all types that implement [`FnMut`], e.g., (safe) -/// [function pointers] (since `FnOnce` is a supertrait of [`FnMut`]). -/// -/// Since both [`Fn`] and [`FnMut`] are subtraits of `FnOnce`, any instance of -/// [`Fn`] or [`FnMut`] can be used where a `FnOnce` is expected. -/// -/// Use `FnOnce` as a bound when you want to accept a parameter of function-like -/// type and only need to call it once. If you need to call the parameter -/// repeatedly, use [`FnMut`] as a bound; if you also need it to not mutate -/// state, use [`Fn`]. -/// -/// See the [chapter on closures in *The Rust Programming Language*][book] for -/// some more information on this topic. -/// -/// Also of note is the special syntax for `Fn` traits (e.g. -/// `Fn(usize, bool) -> usize`). Those interested in the technical details of -/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. -/// -/// [book]: ../../book/ch13-01-closures.html -/// [function pointers]: fn -/// [nomicon]: ../../nomicon/hrtb.html -/// -/// # Examples -/// -/// ## Using a `FnOnce` parameter -/// -/// ``` -/// fn consume_with_relish<F>(func: F) -/// where F: FnOnce() -> String -/// { -/// // `func` consumes its captured variables, so it cannot be run more -/// // than once. -/// println!("Consumed: {}", func()); -/// -/// println!("Delicious!"); -/// -/// // Attempting to invoke `func()` again will throw a `use of moved -/// // value` error for `func`. -/// } -/// -/// let x = String::from("x"); -/// let consume_and_return_x = move || x; -/// consume_with_relish(consume_and_return_x); -/// -/// // `consume_and_return_x` can no longer be invoked at this point -/// ``` -#[cfg(not(bootstrap))] #[lang = "fn_once"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_paren_sugar] @@ -507,68 +250,6 @@ pub trait FnOnce<Args: Tuple> { extern "rust-call" fn call_once(self, args: Args) -> Self::Output; } -#[cfg(bootstrap)] -mod impls { - #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] - impl<A, F: ?Sized> const Fn<A> for &F - where - F: ~const Fn<A>, - { - extern "rust-call" fn call(&self, args: A) -> F::Output { - (**self).call(args) - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] - impl<A, F: ?Sized> const FnMut<A> for &F - where - F: ~const Fn<A>, - { - extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { - (**self).call(args) - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] - impl<A, F: ?Sized> const FnOnce<A> for &F - where - F: ~const Fn<A>, - { - type Output = F::Output; - - extern "rust-call" fn call_once(self, args: A) -> F::Output { - (*self).call(args) - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] - impl<A, F: ?Sized> const FnMut<A> for &mut F - where - F: ~const FnMut<A>, - { - extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { - (*self).call_mut(args) - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] - impl<A, F: ?Sized> const FnOnce<A> for &mut F - where - F: ~const FnMut<A>, - { - type Output = F::Output; - extern "rust-call" fn call_once(self, args: A) -> F::Output { - (*self).call_mut(args) - } - } -} - -#[cfg(not(bootstrap))] mod impls { use crate::marker::Tuple; |