diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 97c2d8e7a8e79..bf8f5b8b91a1e 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -759,13 +759,14 @@ impl<A, F: Fn<A> + ?Sized> Fn<A> for Box<F> {
}
}
+/// `FnBox` is deprecated and will be removed.
+/// `Box<dyn FnOnce()>` can be called directly, since Rust 1.35.0.
+///
/// `FnBox` is a version of the `FnOnce` intended for use with boxed
-/// closure objects. The idea is that where one would normally store a
-/// `Box<dyn FnOnce()>` in a data structure, you should use
+/// closure objects. The idea was that where one would normally store a
+/// `Box<dyn FnOnce()>` in a data structure, you whould use
/// `Box<dyn FnBox()>`. The two traits behave essentially the same, except
-/// that a `FnBox` closure can only be called if it is boxed. (Note
-/// that `FnBox` may be deprecated in the future if `Box<dyn FnOnce()>`
-/// closures become directly usable.)
+/// that a `FnBox` closure can only be called if it is boxed.
///
/// # Examples
///
@@ -777,6 +778,7 @@ impl<A, F: Fn<A> + ?Sized> Fn<A> for Box<F> {
///
/// ```
/// #![feature(fnbox)]
+/// #![allow(deprecated)]
///
/// use std::boxed::FnBox;
/// use std::collections::HashMap;
@@ -796,16 +798,38 @@ impl<A, F: Fn<A> + ?Sized> Fn<A> for Box<F> {
/// }
/// }
/// ```
+///
+/// In Rust 1.35.0 or later, use `FnOnce`, `FnMut`, or `Fn` instead:
+///
+/// ```
+/// use std::collections::HashMap;
+///
+/// fn make_map() -> HashMap<i32, Box<dyn FnOnce() -> i32>> {
+/// let mut map: HashMap<i32, Box<dyn FnOnce() -> i32>> = HashMap::new();
+/// map.insert(1, Box::new(|| 22));
+/// map.insert(2, Box::new(|| 44));
+/// map
+/// }
+///
+/// fn main() {
+/// let mut map = make_map();
+/// for i in &[1, 2] {
+/// let f = map.remove(&i).unwrap();
+/// assert_eq!(f(), i * 22);
+/// }
+/// }
+/// ```
#[rustc_paren_sugar]
-#[unstable(feature = "fnbox",
- reason = "will be deprecated if and when `Box<FnOnce>` becomes usable", issue = "28796")]
+#[unstable(feature = "fnbox", issue = "28796")]
+#[rustc_deprecated(reason = "use `FnOnce`, `FnMut`, or `Fn` instead", since = "1.37.0")]
pub trait FnBox<A>: FnOnce<A> {
/// Performs the call operation.
fn call_box(self: Box<Self>, args: A) -> Self::Output;
}
-#[unstable(feature = "fnbox",
- reason = "will be deprecated if and when `Box<FnOnce>` becomes usable", issue = "28796")]
+#[unstable(feature = "fnbox", issue = "28796")]
+#[rustc_deprecated(reason = "use `FnOnce`, `FnMut`, or `Fn` instead", since = "1.37.0")]
+#[allow(deprecated, deprecated_in_future)]
impl<A, F> FnBox<A> for F
where F: FnOnce<A>
{
diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index 7f7db2a21251a..8bd0d74cd1710 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -22,7 +22,6 @@
#![unstable(feature = "test", issue = "27812")]
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/", test(attr(deny(warnings))))]
#![feature(asm)]
-#![feature(fnbox)]
#![cfg_attr(any(unix, target_os = "cloudabi"), feature(libc, rustc_private))]
#![feature(nll)]
#![feature(set_stdio)]
@@ -56,7 +55,6 @@ pub use self::TestResult::*;
use std::any::Any;
use std::borrow::Cow;
-use std::boxed::FnBox;
use std::cmp;
use std::collections::BTreeMap;
use std::env;
@@ -174,7 +172,7 @@ pub trait TDynBenchFn: Send {
pub enum TestFn {
StaticTestFn(fn()),
StaticBenchFn(fn(&mut Bencher)),
- DynTestFn(Box<dyn FnBox() + Send>),
+ DynTestFn(Box<dyn FnOnce() + Send>),
DynBenchFn(Box<dyn TDynBenchFn + 'static>),
}
@@ -1447,7 +1445,7 @@ pub fn run_test(
desc: TestDesc,
monitor_ch: Sender<MonitorMsg>,
nocapture: bool,
- testfn: Box<dyn FnBox() + Send>,
+ testfn: Box<dyn FnOnce() + Send>,
concurrency: Concurrent,
) {
// Buffer for capturing standard I/O
diff --git a/src/test/run-pass/unsized-locals/fnbox-compat.rs b/src/test/run-pass/unsized-locals/fnbox-compat.rs
index 5ec54ada13bb0..74a4dd5d8515b 100644
--- a/src/test/run-pass/unsized-locals/fnbox-compat.rs
+++ b/src/test/run-pass/unsized-locals/fnbox-compat.rs
@@ -1,4 +1,5 @@
#![feature(fnbox)]
+#![allow(deprecated, deprecated_in_future)]
use std::boxed::FnBox;
diff --git a/src/test/ui/confuse-field-and-method/issue-2392.rs b/src/test/ui/confuse-field-and-method/issue-2392.rs
index 41287c2591497..c242b6c2c20a2 100644
--- a/src/test/ui/confuse-field-and-method/issue-2392.rs
+++ b/src/test/ui/confuse-field-and-method/issue-2392.rs
@@ -1,7 +1,3 @@
-#![feature(core, fnbox)]
-
-use std::boxed::FnBox;
-
struct FuncContainer {
f1: fn(data: u8),
f2: extern "C" fn(data: u8),
@@ -18,7 +14,7 @@ struct Obj<F> where F: FnOnce() -> u32 {
}
struct BoxedObj {
- boxed_closure: Box<FnBox() -> u32>,
+ boxed_closure: Box<FnOnce() -> u32>,
}
struct Wrapper<F> where F: FnMut() -> u32 {
@@ -29,8 +25,8 @@ fn func() -> u32 {
0
}
-fn check_expression() -> Obj<Box<FnBox() -> u32>> {
- Obj { closure: Box::new(|| 42_u32) as Box<FnBox() -> u32>, not_closure: 42 }
+fn check_expression() -> Obj<Box<FnOnce() -> u32>> {
+ Obj { closure: Box::new(|| 42_u32) as Box<FnOnce() -> u32>, not_closure: 42 }
}
fn main() {
@@ -48,7 +44,7 @@ fn main() {
let boxed_fn = BoxedObj { boxed_closure: Box::new(func) };
boxed_fn.boxed_closure();//~ ERROR no method named `boxed_closure` found
- let boxed_closure = BoxedObj { boxed_closure: Box::new(|| 42_u32) as Box<FnBox() -> u32> };
+ let boxed_closure = BoxedObj { boxed_closure: Box::new(|| 42_u32) as Box<FnOnce() -> u32> };
boxed_closure.boxed_closure();//~ ERROR no method named `boxed_closure` found
// test expression writing in the notes
diff --git a/src/test/ui/confuse-field-and-method/issue-2392.stderr b/src/test/ui/confuse-field-and-method/issue-2392.stderr
index 2107318d87b5b..351cfef1b53ea 100644
--- a/src/test/ui/confuse-field-and-method/issue-2392.stderr
+++ b/src/test/ui/confuse-field-and-method/issue-2392.stderr
@@ -1,5 +1,5 @@
-error[E0599]: no method named `closure` found for type `Obj<[closure@$DIR/issue-2392.rs:39:36: 39:41]>` in the current scope
- --> $DIR/issue-2392.rs:40:15
+error[E0599]: no method named `closure` found for type `Obj<[closure@$DIR/issue-2392.rs:35:36: 35:41]>` in the current scope
+ --> $DIR/issue-2392.rs:36:15
|
LL | struct Obj<F> where F: FnOnce() -> u32 {
| -------------------------------------- method `closure` not found for this
@@ -11,8 +11,8 @@ help: to call the function stored in `closure`, surround the field access with p
LL | (o_closure.closure)();
| ^ ^
-error[E0599]: no method named `not_closure` found for type `Obj<[closure@$DIR/issue-2392.rs:39:36: 39:41]>` in the current scope
- --> $DIR/issue-2392.rs:42:15
+error[E0599]: no method named `not_closure` found for type `Obj<[closure@$DIR/issue-2392.rs:35:36: 35:41]>` in the current scope
+ --> $DIR/issue-2392.rs:38:15
|
LL | struct Obj<F> where F: FnOnce() -> u32 {
| -------------------------------------- method `not_closure` not found for this
@@ -23,7 +23,7 @@ LL | o_closure.not_closure();
| field, not a method
error[E0599]: no method named `closure` found for type `Obj<fn() -> u32 {func}>` in the current scope
- --> $DIR/issue-2392.rs:46:12
+ --> $DIR/issue-2392.rs:42:12
|
LL | struct Obj<F> where F: FnOnce() -> u32 {
| -------------------------------------- method `closure` not found for this
@@ -36,7 +36,7 @@ LL | (o_func.closure)();
| ^ ^
error[E0599]: no method named `boxed_closure` found for type `BoxedObj` in the current scope
- --> $DIR/issue-2392.rs:49:14
+ --> $DIR/issue-2392.rs:45:14
|
LL | struct BoxedObj {
| --------------- method `boxed_closure` not found for this
@@ -49,7 +49,7 @@ LL | (boxed_fn.boxed_closure)();
| ^ ^
error[E0599]: no method named `boxed_closure` found for type `BoxedObj` in the current scope
- --> $DIR/issue-2392.rs:52:19
+ --> $DIR/issue-2392.rs:48:19
|
LL | struct BoxedObj {
| --------------- method `boxed_closure` not found for this
@@ -62,7 +62,7 @@ LL | (boxed_closure.boxed_closure)();
| ^ ^
error[E0599]: no method named `closure` found for type `Obj<fn() -> u32 {func}>` in the current scope
- --> $DIR/issue-2392.rs:57:12
+ --> $DIR/issue-2392.rs:53:12
|
LL | struct Obj<F> where F: FnOnce() -> u32 {
| -------------------------------------- method `closure` not found for this
@@ -75,7 +75,7 @@ LL | (w.wrap.closure)();
| ^ ^
error[E0599]: no method named `not_closure` found for type `Obj<fn() -> u32 {func}>` in the current scope
- --> $DIR/issue-2392.rs:59:12
+ --> $DIR/issue-2392.rs:55:12
|
LL | struct Obj<F> where F: FnOnce() -> u32 {
| -------------------------------------- method `not_closure` not found for this
@@ -85,8 +85,8 @@ LL | w.wrap.not_closure();
| |
| field, not a method
-error[E0599]: no method named `closure` found for type `Obj<std::boxed::Box<(dyn std::boxed::FnBox<(), Output = u32> + 'static)>>` in the current scope
- --> $DIR/issue-2392.rs:62:24
+error[E0599]: no method named `closure` found for type `Obj<std::boxed::Box<(dyn std::ops::FnOnce() -> u32 + 'static)>>` in the current scope
+ --> $DIR/issue-2392.rs:58:24
|
LL | struct Obj<F> where F: FnOnce() -> u32 {
| -------------------------------------- method `closure` not found for this
@@ -99,7 +99,7 @@ LL | (check_expression().closure)();
| ^ ^
error[E0599]: no method named `f1` found for type `FuncContainer` in the current scope
- --> $DIR/issue-2392.rs:68:31
+ --> $DIR/issue-2392.rs:64:31
|
LL | struct FuncContainer {
| -------------------- method `f1` not found for this
@@ -112,7 +112,7 @@ LL | ((*self.container).f1)(1);
| ^ ^
error[E0599]: no method named `f2` found for type `FuncContainer` in the current scope
- --> $DIR/issue-2392.rs:69:31
+ --> $DIR/issue-2392.rs:65:31
|
LL | struct FuncContainer {
| -------------------- method `f2` not found for this
@@ -125,7 +125,7 @@ LL | ((*self.container).f2)(1);
| ^ ^
error[E0599]: no method named `f3` found for type `FuncContainer` in the current scope
- --> $DIR/issue-2392.rs:70:31
+ --> $DIR/issue-2392.rs:66:31
|
LL | struct FuncContainer {
| -------------------- method `f3` not found for this