src/librustc_mir/hair/cx/to_ref.rs

   1 // Copyright 2015 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 hair::*;
  12
  13 use rustc::hir;
  14 use syntax::ptr::P;
  15
  16 pub trait ToRef {
  17     type Output;
  18     fn to_ref(self) -> Self::Output;
  19 }
  20
  21 impl<'a, 'tcx: 'a> ToRef for &'tcx hir::Expr {
  22     type Output = ExprRef<'tcx>;
  23
  24     fn to_ref(self) -> ExprRef<'tcx> {
  25         ExprRef::Hair(self)
  26     }
  27 }
  28
  29 impl<'a, 'tcx: 'a> ToRef for &'tcx P<hir::Expr> {
  30     type Output = ExprRef<'tcx>;
  31
  32     fn to_ref(self) -> ExprRef<'tcx> {
  33         ExprRef::Hair(&**self)
  34     }
  35 }
  36
  37 impl<'a, 'tcx: 'a> ToRef for Expr<'tcx> {
  38     type Output = ExprRef<'tcx>;
  39
  40     fn to_ref(self) -> ExprRef<'tcx> {
  41         ExprRef::Mirror(Box::new(self))
  42     }
  43 }
  44
  45 impl<'a, 'tcx: 'a, T, U> ToRef for &'tcx Option<T>
  46     where &'tcx T: ToRef<Output = U>
  47 {
  48     type Output = Option<U>;
  49
  50     fn to_ref(self) -> Option<U> {
  51         self.as_ref().map(|expr| expr.to_ref())
  52     }
  53 }
  54
  55 impl<'a, 'tcx: 'a, T, U> ToRef for &'tcx Vec<T>
  56     where &'tcx T: ToRef<Output = U>
  57 {
  58     type Output = Vec<U>;
  59
  60     fn to_ref(self) -> Vec<U> {
  61         self.iter().map(|expr| expr.to_ref()).collect()
  62     }
  63 }
  64
  65 impl<'a, 'tcx: 'a, T, U> ToRef for &'tcx P<[T]>
  66     where &'tcx T: ToRef<Output = U>
  67 {
  68     type Output = Vec<U>;
  69
  70     fn to_ref(self) -> Vec<U> {
  71         self.iter().map(|expr| expr.to_ref()).collect()
  72     }
  73 }