implement feature tuple_struct_self_ctor

src/test/run-pass/tuple-struct-self-ctor.rs

@@ -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();
+}

src/test/ui/feature-gates/feature-gate-tuple-struct-self-ctor.rs

@@ -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]
+    }
+}

src/test/ui/feature-gates/feature-gate-tuple-struct-self-ctor.stderr

@@ -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`.

src/test/ui/resolve/tuple-struct-alias.rs

@@ -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 {

src/test/ui/resolve/tuple-struct-alias.stderr

@@ -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`.