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first attempt at implementing RFC 1623. This fixes #35897.
This is a work in progress. In particular, I want to add more tests,
especially the compile-fail test is very bare-bones.
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llogiq committed Aug 23, 2016
1 parent 3c5a0fa commit cfce351
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Showing 3 changed files with 74 additions and 1 deletion.
2 changes: 1 addition & 1 deletion src/librustc_typeck/collect.rs
Expand Up @@ -1554,7 +1554,7 @@ fn type_of_def_id<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>,
NodeItem(item) => {
match item.node {
ItemStatic(ref t, _, _) | ItemConst(ref t, _) => {
ccx.icx(&()).to_ty(&ExplicitRscope, &t)
ccx.icx(&()).to_ty(&ElidableRscope::new(ty::ReStatic), &t)
}
ItemFn(ref decl, unsafety, _, abi, ref generics, _) => {
let tofd = AstConv::ty_of_bare_fn(&ccx.icx(generics), unsafety, abi, &decl,
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21 changes: 21 additions & 0 deletions src/test/compile-fail/rfc1623.rs
@@ -0,0 +1,21 @@
// Copyright 2012 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.

#![allow(dead_code)]

fn non_elidable<'a, 'b>(a: &'a u8, b: &'b u8) -> &'a u8 { a }

// the boundaries of elision
static NON_ELIDABLE_FN : &fn(&u8, &u8) -> &u8 = non_elidable;
//~^ERROR: missing lifetime specifier

fn main() {
// nothing to do here
}
52 changes: 52 additions & 0 deletions src/test/run-pass/rfc1623.rs
@@ -0,0 +1,52 @@
// Copyright 2012 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.

#![allow(dead_code)]

// very simple test for a 'static static with default lifetime
static SOME_STATIC_STR : &str = "&'static str";
const SOME_CONST_STR : &str = "&'static str";

// this should be the same as without default:
static SOME_EXPLICIT_STATIC_STR : &'static str = "&'static str";
const SOME_EXPLICIT_CONST_STR : &'static str = "&'static str";

// a function that elides to an unbound lifetime for both in- and output
fn id_u8_slice(arg: &[u8]) -> &[u8] { arg }

// one with a function, argument elided
static SOME_STATIC_SIMPLE_FN : &fn(&[u8]) -> &[u8] = id_u8_slice;
const SOME_CONST_SIMPLE_FN : &fn(&[u8]) -> &[u8] = id_u8_slice;

// this should be the same as without elision
static SOME_STATIC_NON_ELIDED_fN : &fn<'a>(&'a [u8]) -> &'a [u8] = id_u8_slice;
const SOME_CONST_NON_ELIDED_fN : &fn<'a>(&'a [u8]) -> &'a [u8] = id_u8_slice;

// another function that elides, each to a different unbound lifetime
fn multi_args(a: &u8, b: &u8, c: &u8) { }

static SOME_STATIC_MULTI_FN : &fn(&u8, &u8, &u8) = multi_args;
const SOME_CONST_MULTI_FN : &fn(&u8, &u8, &u8) = multi_args;


fn main() {
// make sure that the lifetime is actually elided (and not defaulted)
let x = &[1u8, 2, 3];
SOME_STATIC_SIMPLE_FN(x);
SOME_CONST_SIMPLE_FN(x);

// make sure this works with different lifetimes
let a = &1;
{
let b = &2;
let c = &3;
SOME_CONST_MULTI_FN(a, b, c);
}
}

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