Update test for equivalency to include region binders in object types, add new tests relating to HRTB, consolidate the unboxed_closures and overloaded_calls feature gates.

Author: nikomatsakis

src/doc/reference.md

@@ -2513,11 +2513,6 @@ The currently implemented features of the reference compiler are:
                closure as `once` is unlikely to be supported going forward. So
                they are hidden behind this feature until they are to be removed.
 
-* `overloaded_calls` - Allow implementing the `Fn*` family of traits on user
-                       types, allowing overloading the call operator (`()`).
-                       This feature may still undergo changes before being
-                       stabilized.
-
 * `phase` - Usage of the `#[phase]` attribute allows loading compiler plugins
             for custom lints or syntax extensions. The implementation is
             considered unwholesome and in need of overhaul, and it is not clear
@@ -2560,7 +2555,8 @@ The currently implemented features of the reference compiler are:
 * `trace_macros` - Allows use of the `trace_macros` macro, which is a nasty
                    hack that will certainly be removed.
 
-* `unboxed_closures` - A work in progress feature with many known bugs.
+* `unboxed_closures` - Rust's new closure design, which is currently a work in
+                       progress feature with many known bugs.
 
 * `unsafe_destructor` - Allows use of the `#[unsafe_destructor]` attribute,
                         which is considered wildly unsafe and will be

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

@@ -2264,11 +2264,11 @@ fn try_overloaded_call<'a>(fcx: &FnCtxt,
         fcx.inh.method_map.borrow_mut().insert(method_call, method_callee);
         write_call(fcx, call_expression, output_type);
 
-        if !fcx.tcx().sess.features.borrow().overloaded_calls {
+        if !fcx.tcx().sess.features.borrow().unboxed_closures {
             span_err!(fcx.tcx().sess, call_expression.span, E0056,
                 "overloaded calls are experimental");
             span_help!(fcx.tcx().sess, call_expression.span,
-                "add `#![feature(overloaded_calls)]` to \
+                "add `#![feature(unboxed_closures)]` to \
                 the crate attributes to enable");
         }
 

src/libsyntax/feature_gate.rs

@@ -58,7 +58,6 @@ static KNOWN_FEATURES: &'static [(&'static str, Status)] = &[
     ("quote", Active),
     ("linkage", Active),
     ("struct_inherit", Removed),
-    ("overloaded_calls", Active),
 
     ("quad_precision_float", Removed),
 
@@ -101,7 +100,7 @@ enum Status {
 /// A set of features to be used by later passes.
 pub struct Features {
     pub default_type_params: bool,
-    pub overloaded_calls: bool,
+    pub unboxed_closures: bool,
     pub rustc_diagnostic_macros: bool,
     pub import_shadowing: bool,
     pub visible_private_types: bool,
@@ -112,7 +111,7 @@ impl Features {
     pub fn new() -> Features {
         Features {
             default_type_params: false,
-            overloaded_calls: false,
+            unboxed_closures: false,
             rustc_diagnostic_macros: false,
             import_shadowing: false,
             visible_private_types: false,
@@ -458,7 +457,7 @@ pub fn check_crate(span_handler: &SpanHandler, krate: &ast::Crate) -> (Features,
 
     (Features {
         default_type_params: cx.has_feature("default_type_params"),
-        overloaded_calls: cx.has_feature("overloaded_calls"),
+        unboxed_closures: cx.has_feature("unboxed_closures"),
         rustc_diagnostic_macros: cx.has_feature("rustc_diagnostic_macros"),
         import_shadowing: cx.has_feature("import_shadowing"),
         visible_private_types: cx.has_feature("visible_private_types"),

src/test/auxiliary/issue-18711.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(unboxed_closures, overloaded_calls)]
+#![feature(unboxed_closures)]
 #![crate_type = "rlib"]
 
 pub fn inner<F>(f: F) -> F {

src/test/auxiliary/unboxed-closures-cross-crate.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(unboxed_closures, overloaded_calls)]
+#![feature(unboxed_closures)]
 
 #[inline]
 pub fn has_closures() -> uint {

src/test/bench/shootout-reverse-complement.rs

@@ -40,7 +40,7 @@
 
 // ignore-android see #10393 #13206
 
-#![feature(slicing_syntax, unboxed_closures, overloaded_calls)]
+#![feature(slicing_syntax, unboxed_closures)]
 
 extern crate libc;
 

src/test/bench/shootout-spectralnorm.rs

@@ -41,7 +41,7 @@
 // no-pretty-expanded FIXME #15189
 
 #![allow(non_snake_case)]
-#![feature(unboxed_closures, overloaded_calls)]
+#![feature(unboxed_closures)]
 
 use std::iter::AdditiveIterator;
 use std::mem;

src/test/compile-fail/borrowck-overloaded-call.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(overloaded_calls)]
+#![feature(unboxed_closures)]
 
 use std::ops::{Fn, FnMut, FnOnce};
 

src/test/compile-fail/hrtb-higher-ranker-supertraits-transitive.rs

@@ -0,0 +1,60 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test HRTB supertraits with several levels of expansion required.
+
+trait Foo<'tcx>
+{
+    fn foo(&'tcx self) -> &'tcx int;
+}
+
+trait Bar<'ccx>
+    : for<'tcx> Foo<'tcx>
+{
+    fn bar(&'ccx self) -> &'ccx int;
+}
+
+trait Baz
+    : for<'ccx> Bar<'ccx>
+{
+    fn dummy(&self);
+}
+
+trait Qux
+    : Bar<'static>
+{
+    fn dummy(&self);
+}
+
+fn want_foo_for_any_tcx<F>(f: &F)
+    where F : for<'tcx> Foo<'tcx>
+{
+}
+
+fn want_bar_for_any_ccx<B>(b: &B)
+    where B : for<'ccx> Bar<'ccx>
+{
+}
+
+fn want_baz<B>(b: &B)
+    where B : Baz
+{
+    want_foo_for_any_tcx(b);
+    want_bar_for_any_ccx(b);
+}
+
+fn want_qux<B>(b: &B)
+    where B : Qux
+{
+    want_foo_for_any_tcx(b);
+    want_bar_for_any_ccx(b); //~ ERROR not implemented
+}
+
+fn main() {}

src/test/compile-fail/hrtb-higher-ranker-supertraits.rs

@@ -0,0 +1,58 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test a trait (`Bar`) with a higher-ranked supertrait.
+
+trait Foo<'tcx>
+{
+    fn foo(&'tcx self) -> &'tcx int;
+}
+
+trait Bar<'ccx>
+    : for<'tcx> Foo<'tcx>
+{
+    fn bar(&'ccx self) -> &'ccx int;
+}
+
+fn want_foo_for_some_tcx<'x,F>(f: &'x F)
+    where F : Foo<'x>
+{
+    want_foo_for_some_tcx(f);
+    want_foo_for_any_tcx(f); //~ ERROR not implemented
+}
+
+fn want_foo_for_any_tcx<F>(f: &F)
+    where F : for<'tcx> Foo<'tcx>
+{
+    want_foo_for_some_tcx(f);
+    want_foo_for_any_tcx(f);
+}
+
+fn want_bar_for_some_ccx<'x,B>(b: &B)
+    where B : Bar<'x>
+{
+    want_foo_for_some_tcx(b);
+    want_foo_for_any_tcx(b);
+
+    want_bar_for_some_ccx(b);
+    want_bar_for_any_ccx(b); //~ ERROR not implemented
+}
+
+fn want_bar_for_any_ccx<B>(b: &B)
+    where B : for<'ccx> Bar<'ccx>
+{
+    want_foo_for_some_tcx(b);
+    want_foo_for_any_tcx(b);
+
+    want_bar_for_some_ccx(b);
+    want_bar_for_any_ccx(b);
+}
+
+fn main() {}

src/test/compile-fail/hrtb-identity-fn-borrows.rs

@@ -0,0 +1,35 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that the `'a` in the where clause correctly links the region
+// of the output to the region of the input.
+
+trait FnLike<A,R> {
+    fn call(&self, arg: A) -> R;
+}
+
+fn call_repeatedly<F>(f: F)
+    where F : for<'a> FnLike<&'a int, &'a int>
+{
+    // Result is stored: cannot re-assign `x`
+    let mut x = 3;
+    let y = f.call(&x);
+    x = 5; //~ ERROR cannot assign
+
+    // Result is not stored: can re-assign `x`
+    let mut x = 3;
+    f.call(&x);
+    f.call(&x);
+    f.call(&x);
+    x = 5;
+}
+
+fn main() {
+}

src/test/compile-fail/issue-15094.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(overloaded_calls)]
+#![feature(unboxed_closures)]
 
 use std::{fmt, ops};
 

src/test/compile-fail/issue-18532.rs

@@ -12,7 +12,7 @@
 // when a type error or unconstrained type variable propagates
 // into it.
 
-#![feature(overloaded_calls)]
+#![feature(unboxed_closures)]
 
 fn main() {
     (return)((),());

src/test/compile-fail/overloaded-calls-bad.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(overloaded_calls)]
+#![feature(unboxed_closures)]
 
 use std::ops::FnMut;
 

src/test/compile-fail/overloaded-calls-nontuple.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(overloaded_calls)]
+#![feature(unboxed_closures)]
 
 use std::ops::FnMut;
 

src/test/compile-fail/stage0-clone-contravariant-lifetime.rs

@@ -0,0 +1,43 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// A zero-dependency test that covers some basic traits, default
+// methods, etc.  When mucking about with basic type system stuff I
+// often encounter problems in the iterator trait, so it's useful to
+// have hanging around. -nmatsakis
+
+// error-pattern: requires `start` lang_item
+
+#![no_std]
+#![feature(lang_items)]
+
+#[lang = "sized"]
+pub trait Sized for Sized? {
+    // Empty.
+}
+
+pub mod std {
+    pub mod clone {
+        pub trait Clone {
+            fn clone(&self) -> Self;
+        }
+    }
+}
+
+pub struct ContravariantLifetime<'a>;
+
+impl <'a> ::std::clone::Clone for ContravariantLifetime<'a> {
+    #[inline]
+    fn clone(&self) -> ContravariantLifetime<'a> {
+        match *self { ContravariantLifetime => ContravariantLifetime, }
+    }
+}
+
+fn main() { }

src/test/compile-fail/stage0-cmp.rs

@@ -0,0 +1,40 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+
+// A zero-dependency test that covers some basic traits, default
+// methods, etc.  When mucking about with basic type system stuff I
+// often encounter problems in the iterator trait, so it's useful to
+// have hanging around. -nmatsakis
+
+// error-pattern: requires `start` lang_item
+
+#![no_std]
+#![feature(lang_items)]
+
+#[lang = "sized"]
+pub trait Sized for Sized? {
+    // Empty.
+}
+
+#[unstable = "Definition may change slightly after trait reform"]
+pub trait PartialEq for Sized? {
+    /// This method tests for `self` and `other` values to be equal, and is used by `==`.
+    fn eq(&self, other: &Self) -> bool;
+}
+
+#[cfg(not(stage0))]  // NOTE(stage0): remove cfg after a snapshot
+#[unstable = "Trait is unstable."]
+impl<'a, Sized? T: PartialEq> PartialEq for &'a T {
+    #[inline]
+    fn eq(&self, other: & &'a T) -> bool { PartialEq::eq(*self, *other) }
+}
+
+fn main() { }