提交 f004079d 编写于 作者: J Jared Roesch

Actually commit tests

上级 89d401f6
......@@ -1580,7 +1580,7 @@ pub fn expand_type(t: P<ast::Ty>, fld: &mut MacroExpander) -> P<ast::Ty> {
&fld.cx.parse_sess.span_diagnostic,
"type_macros",
t.span,
"type macros are experimental (see tracking issue: 27336)");
"type macros are experimental (see issue: #27336)");
t
}
}
......
// Copyright 2015 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.
macro_rules! Id {
{ $T:tt } => $T
}
struct Foo<T> {
x: Id!(T)
}
fn main() {
let foo = Foo { x: i32 };
}
// Copyright 2015 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(type_macros)]
use std::ops::*;
#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
struct Nil; // empty HList
#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
struct Cons<H, T: HList>(H, T); // cons cell of HList
// trait to classify valid HLists
trait HList {}
impl HList for Nil {}
impl<H, T: HList> HList for Cons<H, T> {}
// term-level macro for HLists
macro_rules! hlist {
{} => { Nil };
{ $head:expr } => { Cons($head, Nil) };
{ $head:expr, $($tail:expr),* } => { Cons($head, hlist!($($tail),*)) };
}
// type-level macro for HLists
macro_rules! HList {
{} => { Nil };
{ $head:ty } => { Cons<$head, Nil> };
{ $head:ty, $($tail:ty),* } => { Cons<$head, HList!($($tail),*)> };
}
// nil case for HList append
impl<Ys: HList> Add<Ys> for Nil {
type Output = Ys;
fn add(self, rhs: Ys) -> Ys {
rhs
}
}
// cons case for HList append
impl<Rec: HList + Sized, X, Xs: HList, Ys: HList> Add<Ys> for Cons<X, Xs> where
Xs: Add<Ys, Output = Rec>,
{
type Output = Cons<X, Rec>;
fn add(self, rhs: Ys) -> Cons<X, Rec> {
Cons(self.0, self.1 + rhs)
}
}
// type macro Expr allows us to expand the + operator appropriately
macro_rules! Expr {
{ ( $($LHS:tt)+ ) } => { Expr!($($LHS)+) };
{ HList ! [ $($LHS:tt)* ] + $($RHS:tt)+ } => {
<Expr!(HList![$($LHS)*]) as Add<Expr!($($RHS)+)>>::Output
};
{ $LHS:tt + $($RHS:tt)+ } => { <Expr!($LHS) as Add<Expr!($($RHS)+)>>::Output };
{ $LHS:ty } => { $LHS };
}
// test demonstrating term level `xs + ys` and type level `Expr!(Xs + Ys)`
fn main() {
fn aux<Xs: HList, Ys: HList>(xs: Xs, ys: Ys) -> Expr!(Xs + Ys)
where Xs: Add<Ys> {
xs + ys
}
let xs: HList![&str, bool, Vec<u64>] = hlist!["foo", false, vec![]];
let ys: HList![u64, [u8; 3], ()] = hlist![0, [0, 1, 2], ()];
// demonstrate recursive expansion of Expr!
let zs: Expr!((HList![&str] + HList![bool] + HList![Vec<u64>]) +
(HList![u64] + HList![[u8; 3], ()]) +
HList![])
= aux(xs, ys);
assert_eq!(zs, hlist!["foo", false, vec![], 0, [0, 1, 2], ()])
}
// Copyright 2015 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(type_macros)]
macro_rules! Tuple {
{ $A:ty,$B:ty } => { ($A, $B) }
}
fn main() {
let x: Tuple!(i32, i32) = (1, 2);
}
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