src/librustc_mir/build/into.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 //! In general, there are a number of things for which it's convenient
  12 //! to just call `builder.into` and have it emit its result into a
  13 //! given location. This is basically for expressions or things that can be
  14 //! wrapped up as expressions (e.g. blocks). To make this ergonomic, we use this
  15 //! latter `EvalInto` trait.
  16
  17 use build::{BlockAnd, Builder};
  18 use hair::*;
  19 use rustc::mir::repr::*;
  20
  21 pub trait EvalInto<'tcx> {
  22     fn eval_into<'a>(self,
  23                      builder: &mut Builder<'a, 'tcx>,
  24                      destination: &Lvalue<'tcx>,
  25                      block: BasicBlock)
  26                      -> BlockAnd<()>;
  27 }
  28
  29 impl<'a,'tcx> Builder<'a,'tcx> {
  30     pub fn into<E>(&mut self,
  31                    destination: &Lvalue<'tcx>,
  32                    block: BasicBlock,
  33                    expr: E)
  34                    -> BlockAnd<()>
  35         where E: EvalInto<'tcx>
  36     {
  37         expr.eval_into(self, destination, block)
  38     }
  39 }
  40
  41 impl<'tcx> EvalInto<'tcx> for ExprRef<'tcx> {
  42     fn eval_into<'a>(self,
  43                      builder: &mut Builder<'a, 'tcx>,
  44                      destination: &Lvalue<'tcx>,
  45                      block: BasicBlock)
  46                      -> BlockAnd<()> {
  47         let expr = builder.hir.mirror(self);
  48         builder.into_expr(destination, block, expr)
  49     }
  50 }
  51
  52 impl<'tcx> EvalInto<'tcx> for Expr<'tcx> {
  53     fn eval_into<'a>(self,
  54                      builder: &mut Builder<'a, 'tcx>,
  55                      destination: &Lvalue<'tcx>,
  56                      block: BasicBlock)
  57                      -> BlockAnd<()> {
  58         builder.into_expr(destination, block, self)
  59     }
  60 }