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nikomatsakisnikomatsakis
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Add blanket impls to allow the various Fn traits to be interconverted.
Fixes rust-lang#18387.
1 parent 63c4f22 commit 680d579

10 files changed

+221
-26
lines changed

‎src/libcore/ops.rs

+50-20
Original file line numberDiff line numberDiff line change
@@ -866,34 +866,64 @@ pub trait FnOnce<Args,Result> {
866866
extern "rust-call" fn call_once(self, args: Args) -> Result;
867867
}
868868

869-
macro_rules! def_fn_mut(
869+
impl<F,A,R> FnMut<A,R> for F
870+
where F : Fn<A,R>
871+
{
872+
extern "rust-call" fn call_mut(&mut self, args: A) -> R {
873+
self.call(args)
874+
}
875+
}
876+
877+
impl<F,A,R> FnOnce<A,R> for F
878+
where F : FnMut<A,R>
879+
{
880+
extern "rust-call" fn call_once(mut self, args: A) -> R {
881+
self.call_mut(args)
882+
}
883+
}
884+
885+
886+
impl<Result> Fn<(),Result> for extern "Rust" fn() -> Result {
887+
#[allow(non_snake_case)]
888+
extern "rust-call" fn call(&self, _args: ()) -> Result {
889+
(*self)()
890+
}
891+
}
892+
893+
impl<Result,A0> Fn<(A0,),Result> for extern "Rust" fn(A0) -> Result {
894+
#[allow(non_snake_case)]
895+
extern "rust-call" fn call(&self, args: (A0,)) -> Result {
896+
let (a0,) = args;
897+
(*self)(a0)
898+
}
899+
}
900+
901+
macro_rules! def_fn(
870902
($($args:ident)*) => (
871903
impl<Result$(,$args)*>
872-
FnMut<($($args,)*),Result>
904+
Fn<($($args,)*),Result>
873905
for extern "Rust" fn($($args: $args,)*) -> Result {
874906
#[allow(non_snake_case)]
875-
extern "rust-call" fn call_mut(&mut self, args: ($($args,)*)) -> Result {
907+
extern "rust-call" fn call(&self, args: ($($args,)*)) -> Result {
876908
let ($($args,)*) = args;
877909
(*self)($($args,)*)
878910
}
879911
}
880912
)
881913
)
882914

883-
def_fn_mut!()
884-
def_fn_mut!(A0)
885-
def_fn_mut!(A0 A1)
886-
def_fn_mut!(A0 A1 A2)
887-
def_fn_mut!(A0 A1 A2 A3)
888-
def_fn_mut!(A0 A1 A2 A3 A4)
889-
def_fn_mut!(A0 A1 A2 A3 A4 A5)
890-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6)
891-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7)
892-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8)
893-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9)
894-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10)
895-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11)
896-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12)
897-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13)
898-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14)
899-
def_fn_mut!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15)
915+
def_fn!(A0 A1)
916+
def_fn!(A0 A1 A2)
917+
def_fn!(A0 A1 A2 A3)
918+
def_fn!(A0 A1 A2 A3 A4)
919+
def_fn!(A0 A1 A2 A3 A4 A5)
920+
def_fn!(A0 A1 A2 A3 A4 A5 A6)
921+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7)
922+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8)
923+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9)
924+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10)
925+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11)
926+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12)
927+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13)
928+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14)
929+
def_fn!(A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15)

‎src/librustc/middle/traits/select.rs

+3-3
Original file line numberDiff line numberDiff line change
@@ -804,12 +804,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
804804
&candidates[i],
805805
&candidates[j]));
806806
if is_dup {
807-
debug!("Dropping candidate #{}/#{}: {}",
807+
debug!("Dropping candidate #{}/{}: {}",
808808
i, candidates.len(), candidates[i].repr(self.tcx()));
809809
candidates.swap_remove(i);
810810
} else {
811-
debug!("Retaining candidate #{}/#{}",
812-
i, candidates.len());
811+
debug!("Retaining candidate #{}/{}: {}",
812+
i, candidates.len(), candidates[i].repr(self.tcx()));
813813
i += 1;
814814
}
815815
}

‎src/librustc/middle/typeck/check/mod.rs

+5
Original file line numberDiff line numberDiff line change
@@ -3493,6 +3493,11 @@ fn check_expr_with_unifier(fcx: &FnCtxt,
34933493
ast::FnOnceUnboxedClosureKind => ty::FnOnceUnboxedClosureKind,
34943494
};
34953495

3496+
debug!("unboxed_closure for {} --> sig={} kind={}",
3497+
local_def(expr.id).repr(fcx.tcx()),
3498+
fn_ty.sig.repr(fcx.tcx()),
3499+
kind);
3500+
34963501
let unboxed_closure = ty::UnboxedClosure {
34973502
closure_type: fn_ty,
34983503
kind: kind,

‎src/test/compile-fail/unboxed-closures-fnmut-as-fn.rs

+34
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,34 @@
1+
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// Checks that the Fn trait hierarchy rules do not permit
12+
// Fn to be used where FnMut is implemented.
13+
14+
#![feature(unboxed_closure_sugar)]
15+
#![feature(overloaded_calls)]
16+
17+
use std::ops::{Fn,FnMut,FnOnce};
18+
19+
struct S;
20+
21+
impl FnMut<(int,),int> for S {
22+
extern "rust-call" fn call_mut(&mut self, (x,): (int,)) -> int {
23+
x * x
24+
}
25+
}
26+
27+
fn call_it<F:Fn(int)->int>(f: &F, x: int) -> int {
28+
f.call((x,))
29+
}
30+
31+
fn main() {
32+
let x = call_it(&S, 22); //~ ERROR not implemented
33+
}
34+

‎src/test/run-pass/issue-16668.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -20,8 +20,8 @@ impl<'a, I, O: 'a> Parser<'a, I, O> {
2020
fn compose<K: 'a>(mut self, mut rhs: Parser<'a, O, K>) -> Parser<'a, I, K> {
2121
Parser {
2222
parse: box move |&mut: x: I| {
23-
match self.parse.call_mut((x,)) {
24-
Ok(r) => rhs.parse.call_mut((r,)),
23+
match (*self.parse).call_mut((x,)) {
24+
Ok(r) => (*rhs.parse).call_mut((r,)),
2525
Err(e) => Err(e)
2626
}
2727
}

‎src/test/run-pass/unboxed-closures-extern-fn.rs

+40
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,40 @@
1+
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// Checks that extern fn points implement the full range of Fn traits.
12+
13+
#![feature(unboxed_closure_sugar)]
14+
#![feature(overloaded_calls)]
15+
16+
use std::ops::{Fn,FnMut,FnOnce};
17+
18+
fn square(x: int) -> int { x * x }
19+
20+
fn call_it<F:Fn(int)->int>(f: &F, x: int) -> int {
21+
f.call((x,))
22+
}
23+
24+
fn call_it_mut<F:FnMut(int)->int>(f: &mut F, x: int) -> int {
25+
f.call_mut((x,))
26+
}
27+
28+
fn call_it_once<F:FnOnce(int)->int>(f: F, x: int) -> int {
29+
f.call_once((x,))
30+
}
31+
32+
fn main() {
33+
let x = call_it(&square, 22);
34+
let y = call_it_mut(&mut square, 22);
35+
let z = call_it_once(square, 22);
36+
assert_eq!(x, square(22));
37+
assert_eq!(y, square(22));
38+
assert_eq!(z, square(22));
39+
}
40+

‎src/test/run-pass/unboxed-closures-fn-as-fnmut-and-fnonce.rs

+46
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,46 @@
1+
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// Checks that the Fn trait hierarchy rules permit
12+
// any Fn trait to be used where Fn is implemented.
13+
14+
#![feature(unboxed_closure_sugar)]
15+
#![feature(overloaded_calls)]
16+
17+
use std::ops::{Fn,FnMut,FnOnce};
18+
19+
struct S;
20+
21+
impl Fn<(int,),int> for S {
22+
extern "rust-call" fn call(&self, (x,): (int,)) -> int {
23+
x * x
24+
}
25+
}
26+
27+
fn call_it<F:Fn(int)->int>(f: &F, x: int) -> int {
28+
f.call((x,))
29+
}
30+
31+
fn call_it_mut<F:FnMut(int)->int>(f: &mut F, x: int) -> int {
32+
f.call_mut((x,))
33+
}
34+
35+
fn call_it_once<F:FnOnce(int)->int>(f: F, x: int) -> int {
36+
f.call_once((x,))
37+
}
38+
39+
fn main() {
40+
let x = call_it(&S, 22);
41+
let y = call_it_mut(&mut S, 22);
42+
let z = call_it_once(S, 22);
43+
assert_eq!(x, y);
44+
assert_eq!(y, z);
45+
}
46+

‎src/test/run-pass/unboxed-closures-fnmut-as-fnonce.rs

+40
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,40 @@
1+
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// Checks that the Fn trait hierarchy rules permit
12+
// FnMut or FnOnce to be used where FnMut is implemented.
13+
14+
#![feature(unboxed_closure_sugar)]
15+
#![feature(overloaded_calls)]
16+
17+
use std::ops::{FnMut,FnOnce};
18+
19+
struct S;
20+
21+
impl FnMut<(int,),int> for S {
22+
extern "rust-call" fn call_mut(&mut self, (x,): (int,)) -> int {
23+
x * x
24+
}
25+
}
26+
27+
fn call_it_mut<F:FnMut(int)->int>(f: &mut F, x: int) -> int {
28+
f.call_mut((x,))
29+
}
30+
31+
fn call_it_once<F:FnOnce(int)->int>(f: F, x: int) -> int {
32+
f.call_once((x,))
33+
}
34+
35+
fn main() {
36+
let y = call_it_mut(&mut S, 22);
37+
let z = call_it_once(S, 22);
38+
assert_eq!(y, z);
39+
}
40+

‎src/test/run-pass/fn-trait-sugar.rs ‎src/test/run-pass/unboxed-closures-manual-impl.rs

File renamed without changes.

‎src/test/run-pass/unboxed-closures-zero-args.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,6 @@
1212

1313
fn main() {
1414
let mut zero = |&mut:| {};
15-
zero.call_mut(());
15+
let () = zero.call_mut(());
1616
}
1717

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