31 lines
925 B
Rust
31 lines
925 B
Rust
// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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/// A compile-time map from identifiers to arbitrary (heterogeneous) expressions
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macro_rules! ident_map {
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( $name:ident = { $($key:ident => $e:expr,)* } ) => {
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macro_rules! $name {
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$(
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( $key ) => { $e };
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)*
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// Empty invocation expands to nothing. Needed when the map is empty.
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() => {};
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}
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};
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}
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ident_map!(my_map = {
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main => 0,
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});
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fn main() {
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my_map!(main);
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}
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