src/libsyntax/ext/deriving/bounds.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use ast::{MetaItem, MetaWord, Item};
  12 use codemap::Span;
  13 use ext::base::ExtCtxt;
  14 use ext::deriving::generic::*;
  15 use ext::deriving::generic::ty::*;
  16
  17 pub fn expand_deriving_bound(cx: &mut ExtCtxt,
  18                              span: Span,
  19                              mitem: @MetaItem,
  20                              item: @Item,
  21                              push: |@Item|) {
  22
  23     let name = match mitem.node {
  24         MetaWord(ref tname) => {
  25             match tname.get() {
  26                 "Copy" => "Copy",
  27                 "Send" => "Send",
  28                 "Share" => "Share",
  29                 ref tname => {
  30                     cx.span_bug(span,
  31                                 format!("expected built-in trait name but \
  32                                          found {}",
  33                                         *tname).as_slice())
  34                 }
  35             }
  36         },
  37         _ => {
  38             return cx.span_err(span, "unexpected value in deriving, expected \
  39                                       a trait")
  40         }
  41     };
  42
  43     let trait_def = TraitDef {
  44         span: span,
  45         attributes: Vec::new(),
  46         path: Path::new(vec!("std", "kinds", name)),
  47         additional_bounds: Vec::new(),
  48         generics: LifetimeBounds::empty(),
  49         methods: vec!()
  50     };
  51
  52     trait_def.expand(cx, mitem, item, push)
  53 }