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// Copyright 2017 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! enum_number {
($name:ident { $($variant:ident = $value:expr, )* }) => {
enum $name {
$($variant = $value,)*
}
fn foo(value: i32) -> Option<$name> {
match value {
$( $value => Some($name::$variant), )* // PatKind::Lit
$( $value ..= 42 => Some($name::$variant), )* // PatKind::Range
_ => None
}
}
}
}
enum_number!(Change {
Pos = 1,
Neg = -1,
Arith = 1 + 1, //~ ERROR arbitrary expressions aren't allowed in patterns
//~^ ERROR only char and numeric types are allowed in range patterns
});
fn main() {}
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