implement feature tuple_struct_self_ctor
This commit is contained in:
parent
f2302daef3
commit
a489169912
9 changed files with 255 additions and 42 deletions
|
@ -0,0 +1,33 @@
|
|||
# `tuple_struct_self_ctor`
|
||||
|
||||
The tracking issue for this feature is: [#51994]
|
||||
[#51994]: https://github.com/rust-lang/rust/issues/51994
|
||||
|
||||
------------------------
|
||||
|
||||
The `tuple_struct_self_ctor` feature gate lets you use the special `Self`
|
||||
identifier as a constructor and a pattern.
|
||||
|
||||
A simple example is:
|
||||
|
||||
```rust
|
||||
#![feature(tuple_struct_self_ctor)]
|
||||
|
||||
struct ST(i32, i32);
|
||||
|
||||
impl ST {
|
||||
fn new() -> Self {
|
||||
ST(0, 1)
|
||||
}
|
||||
|
||||
fn ctor() -> Self {
|
||||
Self(1,2) // constructed by `Self`, it is the same as `ST(1, 2)`
|
||||
}
|
||||
|
||||
fn pattern(self) {
|
||||
match self {
|
||||
Self(x, y) => println!("{} {}", x, y), // used as a pattern
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
|
@ -585,6 +585,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
|
|||
CtorKind::from_ast(struct_def));
|
||||
self.define(parent, ident, ValueNS, (ctor_def, ctor_vis, sp, expansion));
|
||||
self.struct_constructors.insert(def.def_id(), (ctor_def, ctor_vis));
|
||||
self.tuple_structs.insert(def.def_id(), ctor_def);
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -703,6 +704,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
|
|||
self.cstore.def_key(def_id).parent
|
||||
.map(|index| DefId { krate: def_id.krate, index: index }) {
|
||||
self.struct_constructors.insert(struct_def_id, (def, vis));
|
||||
self.tuple_structs.insert(struct_def_id, def);
|
||||
}
|
||||
}
|
||||
Def::Trait(..) => {
|
||||
|
|
|
@ -1463,6 +1463,9 @@ pub struct Resolver<'a, 'b: 'a> {
|
|||
/// it's not used during normal resolution, only for better error reporting.
|
||||
struct_constructors: DefIdMap<(Def, ty::Visibility)>,
|
||||
|
||||
/// Map from tuple struct's DefId to VariantData's Def
|
||||
tuple_structs: DefIdMap<Def>,
|
||||
|
||||
/// Only used for better errors on `fn(): fn()`
|
||||
current_type_ascription: Vec<Span>,
|
||||
|
||||
|
@ -1764,6 +1767,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
|
|||
warned_proc_macros: FxHashSet(),
|
||||
potentially_unused_imports: Vec::new(),
|
||||
struct_constructors: DefIdMap(),
|
||||
tuple_structs: DefIdMap(),
|
||||
found_unresolved_macro: false,
|
||||
unused_macros: FxHashSet(),
|
||||
current_type_ascription: Vec::new(),
|
||||
|
@ -2204,6 +2208,19 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
|
|||
None
|
||||
}
|
||||
|
||||
fn resolve_adt(&mut self, item: &Item, generics: &Generics) {
|
||||
self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
|
||||
let item_def_id = this.definitions.local_def_id(item.id);
|
||||
if this.session.features_untracked().self_in_typedefs {
|
||||
this.with_self_rib(Def::SelfTy(None, Some(item_def_id)), |this| {
|
||||
visit::walk_item(this, item);
|
||||
});
|
||||
} else {
|
||||
visit::walk_item(this, item);
|
||||
}
|
||||
});
|
||||
}
|
||||
|
||||
fn resolve_item(&mut self, item: &Item) {
|
||||
let name = item.ident.name;
|
||||
debug!("(resolving item) resolving {}", name);
|
||||
|
@ -2216,19 +2233,25 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
|
|||
|this| visit::walk_item(this, item));
|
||||
}
|
||||
|
||||
ItemKind::Enum(_, ref generics) |
|
||||
ItemKind::Struct(_, ref generics) |
|
||||
ItemKind::Union(_, ref generics) => {
|
||||
self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
|
||||
let item_def_id = this.definitions.local_def_id(item.id);
|
||||
if this.session.features_untracked().self_in_typedefs {
|
||||
this.with_self_rib(Def::SelfTy(None, Some(item_def_id)), |this| {
|
||||
visit::walk_item(this, item);
|
||||
});
|
||||
} else {
|
||||
visit::walk_item(this, item);
|
||||
ItemKind::Struct(ref variant, ref generics) => {
|
||||
if variant.is_tuple() || variant.is_unit() {
|
||||
if let Some(def_id) = self.definitions.opt_local_def_id(item.id) {
|
||||
if let Some(variant_id) = self.definitions.opt_local_def_id(variant.id()) {
|
||||
let variant_def = if variant.is_tuple() {
|
||||
Def::StructCtor(variant_id, CtorKind::Fn)
|
||||
} else {
|
||||
Def::StructCtor(variant_id, CtorKind::Const)
|
||||
};
|
||||
self.tuple_structs.insert(def_id, variant_def);
|
||||
}
|
||||
}
|
||||
});
|
||||
}
|
||||
self.resolve_adt(item, generics);
|
||||
}
|
||||
|
||||
ItemKind::Enum(_, ref generics) |
|
||||
ItemKind::Union(_, ref generics) => {
|
||||
self.resolve_adt(item, generics);
|
||||
}
|
||||
|
||||
ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
|
||||
|
@ -2503,6 +2526,32 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
|
|||
self.ribs[TypeNS].pop();
|
||||
}
|
||||
|
||||
fn with_tuple_struct_self_ctor_rib<F>(&mut self, self_ty: &Ty, f: F)
|
||||
where F: FnOnce(&mut Resolver)
|
||||
{
|
||||
let variant_def = if self.session.features_untracked().tuple_struct_self_ctor {
|
||||
let base_def = self.def_map.get(&self_ty.id).map(|r| r.base_def());
|
||||
if let Some(Def::Struct(ref def_id)) = base_def {
|
||||
self.tuple_structs.get(def_id).cloned()
|
||||
} else {
|
||||
None
|
||||
}
|
||||
} else {
|
||||
None
|
||||
};
|
||||
|
||||
// when feature gate is enabled and `Self` is a tuple struct
|
||||
if let Some(variant_def) = variant_def {
|
||||
let mut self_type_rib = Rib::new(NormalRibKind);
|
||||
self_type_rib.bindings.insert(keywords::SelfType.ident(), variant_def);
|
||||
self.ribs[ValueNS].push(self_type_rib);
|
||||
f(self);
|
||||
self.ribs[ValueNS].pop();
|
||||
} else {
|
||||
f(self);
|
||||
}
|
||||
}
|
||||
|
||||
fn resolve_implementation(&mut self,
|
||||
generics: &Generics,
|
||||
opt_trait_reference: &Option<TraitRef>,
|
||||
|
@ -2554,8 +2603,9 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
|
|||
ValueNS,
|
||||
impl_item.span,
|
||||
|n, s| MethodNotMemberOfTrait(n, s));
|
||||
|
||||
visit::walk_impl_item(this, impl_item);
|
||||
this.with_tuple_struct_self_ctor_rib(self_type, |this| {
|
||||
visit::walk_impl_item(this, impl_item);
|
||||
});
|
||||
}
|
||||
ImplItemKind::Type(ref ty) => {
|
||||
// If this is a trait impl, ensure the type
|
||||
|
|
|
@ -512,6 +512,9 @@ declare_features! (
|
|||
|
||||
// Non-builtin attributes in inner attribute position
|
||||
(active, custom_inner_attributes, "1.30.0", Some(38356), None),
|
||||
|
||||
// tuple struct self constructor (RFC 2302)
|
||||
(active, tuple_struct_self_ctor, "1.31.0", Some(51994), None),
|
||||
);
|
||||
|
||||
declare_features! (
|
||||
|
@ -1736,6 +1739,15 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
|
|||
ast::ExprKind::Async(..) => {
|
||||
gate_feature_post!(&self, async_await, e.span, "async blocks are unstable");
|
||||
}
|
||||
ast::ExprKind::Call(ref callee, _) => {
|
||||
if let ast::ExprKind::Path(_, ref p) = callee.node {
|
||||
if p.segments.len() == 1 &&
|
||||
p.segments[0].ident.name == keywords::SelfType.name() {
|
||||
gate_feature_post!(&self, tuple_struct_self_ctor, e.span,
|
||||
"tuple struct Self constructors are unstable");
|
||||
}
|
||||
}
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
visit::walk_expr(self, e);
|
||||
|
|
102
src/test/run-pass/tuple-struct-self-ctor.rs
Normal file
102
src/test/run-pass/tuple-struct-self-ctor.rs
Normal file
|
@ -0,0 +1,102 @@
|
|||
// Copyright 2018 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.
|
||||
|
||||
#![feature(tuple_struct_self_ctor)]
|
||||
|
||||
#![allow(dead_code)]
|
||||
|
||||
use std::fmt::Display;
|
||||
|
||||
struct ST1(i32, i32);
|
||||
|
||||
impl ST1 {
|
||||
fn new() -> Self {
|
||||
ST1(0, 1)
|
||||
}
|
||||
|
||||
fn ctor() -> Self {
|
||||
Self(1,2) // Self as a constructor
|
||||
}
|
||||
|
||||
fn pattern(self) {
|
||||
match self {
|
||||
Self(x, y) => println!("{} {}", x, y), // Self as a pattern
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct ST2<T>(T); // With type parameter
|
||||
|
||||
impl<T> ST2<T> where T: Display {
|
||||
|
||||
fn ctor(v: T) -> Self {
|
||||
Self(v)
|
||||
}
|
||||
|
||||
fn pattern(&self) {
|
||||
match self {
|
||||
Self(ref v) => println!("{}", v),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct ST3<'a>(&'a i32); // With lifetime parameter
|
||||
|
||||
impl<'a> ST3<'a> {
|
||||
|
||||
fn ctor(v: &'a i32) -> Self {
|
||||
Self(v)
|
||||
}
|
||||
|
||||
fn pattern(self) {
|
||||
let Self(ref v) = self;
|
||||
println!("{}", v);
|
||||
}
|
||||
}
|
||||
|
||||
struct ST4(usize);
|
||||
|
||||
impl ST4 {
|
||||
fn map(opt: Option<usize>) -> Option<Self> {
|
||||
opt.map(Self) // use `Self` as a function passed somewhere
|
||||
}
|
||||
}
|
||||
|
||||
struct ST5; // unit struct
|
||||
|
||||
impl ST5 {
|
||||
fn ctor() -> Self {
|
||||
Self // `Self` as a unit struct value
|
||||
}
|
||||
|
||||
fn pattern(self) -> Self {
|
||||
match self {
|
||||
Self => Self, // `Self` as a unit struct value for matching
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn main() {
|
||||
let v1 = ST1::ctor();
|
||||
v1.pattern();
|
||||
|
||||
let v2 = ST2::ctor(10);
|
||||
v2.pattern();
|
||||
|
||||
let local = 42;
|
||||
let v3 = ST3::ctor(&local);
|
||||
v3.pattern();
|
||||
|
||||
let v4 = Some(1usize);
|
||||
let _ = ST4::map(v4);
|
||||
|
||||
let v5 = ST5::ctor();
|
||||
v5.pattern();
|
||||
}
|
|
@ -0,0 +1,19 @@
|
|||
// Copyright 2018 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.
|
||||
|
||||
struct ST(i32, i32);
|
||||
|
||||
impl ST {
|
||||
fn ctor() -> Self {
|
||||
Self(1,2)
|
||||
//~^ ERROR: expected function, found self type `Self` [E0423]
|
||||
//~^^ ERROR: tuple struct Self constructors are unstable (see issue #51994) [E0658]
|
||||
}
|
||||
}
|
|
@ -0,0 +1,20 @@
|
|||
error[E0423]: expected function, found self type `Self`
|
||||
--> $DIR/feature-gate-tuple-struct-self-ctor.rs:15:9
|
||||
|
|
||||
LL | Self(1,2)
|
||||
| ^^^^ not a function
|
||||
|
|
||||
= note: can't use `Self` as a constructor, you must use the implemented struct
|
||||
|
||||
error[E0658]: tuple struct Self constructors are unstable (see issue #51994)
|
||||
--> $DIR/feature-gate-tuple-struct-self-ctor.rs:15:9
|
||||
|
|
||||
LL | Self(1,2)
|
||||
| ^^^^^^^^^
|
||||
|
|
||||
= help: add #![feature(tuple_struct_self_ctor)] to the crate attributes to enable
|
||||
|
||||
error: aborting due to 2 previous errors
|
||||
|
||||
Some errors occurred: E0423, E0658.
|
||||
For more information about an error, try `rustc --explain E0423`.
|
|
@ -11,15 +11,6 @@
|
|||
struct S(u8, u16);
|
||||
type A = S;
|
||||
|
||||
impl S {
|
||||
fn f() {
|
||||
let s = Self(0, 1); //~ ERROR expected function
|
||||
match s {
|
||||
Self(..) => {} //~ ERROR expected tuple struct/variant
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn main() {
|
||||
let s = A(0, 1); //~ ERROR expected function
|
||||
match s {
|
||||
|
|
|
@ -1,21 +1,5 @@
|
|||
error[E0423]: expected function, found self type `Self`
|
||||
--> $DIR/tuple-struct-alias.rs:16:17
|
||||
|
|
||||
LL | let s = Self(0, 1); //~ ERROR expected function
|
||||
| ^^^^ not a function
|
||||
|
|
||||
= note: can't use `Self` as a constructor, you must use the implemented struct
|
||||
|
||||
error[E0532]: expected tuple struct/variant, found self type `Self`
|
||||
--> $DIR/tuple-struct-alias.rs:18:13
|
||||
|
|
||||
LL | Self(..) => {} //~ ERROR expected tuple struct/variant
|
||||
| ^^^^ not a tuple struct/variant
|
||||
|
|
||||
= note: can't use `Self` as a constructor, you must use the implemented struct
|
||||
|
||||
error[E0423]: expected function, found type alias `A`
|
||||
--> $DIR/tuple-struct-alias.rs:24:13
|
||||
--> $DIR/tuple-struct-alias.rs:15:13
|
||||
|
|
||||
LL | let s = A(0, 1); //~ ERROR expected function
|
||||
| ^ did you mean `S`?
|
||||
|
@ -23,14 +7,14 @@ LL | let s = A(0, 1); //~ ERROR expected function
|
|||
= note: can't use a type alias as a constructor
|
||||
|
||||
error[E0532]: expected tuple struct/variant, found type alias `A`
|
||||
--> $DIR/tuple-struct-alias.rs:26:9
|
||||
--> $DIR/tuple-struct-alias.rs:17:9
|
||||
|
|
||||
LL | A(..) => {} //~ ERROR expected tuple struct/variant
|
||||
| ^ did you mean `S`?
|
||||
|
|
||||
= note: can't use a type alias as a constructor
|
||||
|
||||
error: aborting due to 4 previous errors
|
||||
error: aborting due to 2 previous errors
|
||||
|
||||
Some errors occurred: E0423, E0532.
|
||||
For more information about an error, try `rustc --explain E0423`.
|
||||
|
|
Loading…
Reference in a new issue