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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.
use ast::{MetaItem, Item, Expr};
use codemap::Span;
use ext::base::ExtCtxt;
use ext::build::AstBuilder;
use ext::deriving::generic::*;
pub fn expand_deriving_eq(cx: &mut ExtCtxt,
span: Span,
mitem: @MetaItem,
item: @Item,
push: |@Item|) {
// structures are equal if all fields are equal, and non equal, if
// any fields are not equal or if the enum variants are different
fn cs_eq(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> @Expr {
cs_and(|cx, span, _, _| cx.expr_bool(span, false),
cx, span, substr)
}
fn cs_ne(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> @Expr {
cs_or(|cx, span, _, _| cx.expr_bool(span, true),
cx, span, substr)
}
macro_rules! md (
($name:expr, $f:ident) => {
MethodDef {
name: $name,
generics: LifetimeBounds::empty(),
explicit_self: borrowed_explicit_self(),
args: vec!(borrowed_self()),
ret_ty: Literal(Path::new(vec!("bool"))),
inline: true,
const_nonmatching: true,
combine_substructure: $f
}
}
);
let trait_def = TraitDef {
span: span,
attributes: Vec::new(),
path: Path::new(vec!("std", "cmp", "Eq")),
additional_bounds: Vec::new(),
generics: LifetimeBounds::empty(),
methods: vec!(
md!("eq", cs_eq),
md!("ne", cs_ne)
)
};
trait_def.expand(cx, mitem, item, push)
}
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