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// Copyright 2013 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.
// Constants (static variables) can be used to match in patterns, but mutable
// statics cannot. This ensures that there's some form of error if this is
// attempted.
static mut a: isize = 3;
fn main() {
// If they can't be matched against, then it's possible to capture the same
// name as a variable, hence this should be an unreachable pattern situation
// instead of spitting out a custom error about some identifier collisions
// (we should allow shadowing)
match 4 {
a => {} //~ ERROR static variables cannot be referenced in a pattern
_ => {}
}
}
struct NewBool(bool);
enum Direction {
North,
East,
South,
West
}
const NEW_FALSE: NewBool = NewBool(false);
struct Foo {
bar: Option<Direction>,
baz: NewBool
}
static mut STATIC_MUT_FOO: Foo = Foo { bar: Some(Direction::West), baz: NEW_FALSE };
fn mutable_statics() {
match (Foo { bar: Some(Direction::North), baz: NewBool(true) }) {
Foo { bar: None, baz: NewBool(true) } => (),
STATIC_MUT_FOO => (),
//~^ ERROR static variables cannot be referenced in a pattern
Foo { bar: Some(Direction::South), .. } => (),
Foo { bar: Some(EAST), .. } => (),
Foo { bar: Some(Direction::North), baz: NewBool(true) } => (),
Foo { bar: Some(EAST), baz: NewBool(false) } => ()
}
}
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