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.
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.
11 //! See docs in build/expr/mod.rs
15 use rustc
::mir
::repr
::*;
17 impl<'a
,'tcx
> Builder
<'a
,'tcx
> {
18 /// Compile `expr`, yielding a compile-time constant. Assumes that
19 /// `expr` is a valid compile-time constant!
20 pub fn as_constant
<M
>(&mut self, expr
: M
) -> Constant
<'tcx
>
21 where M
: Mirror
<'tcx
, Output
=Expr
<'tcx
>>
23 let expr
= self.hir
.mirror(expr
);
24 self.expr_as_constant(expr
)
27 fn expr_as_constant(&mut self, expr
: Expr
<'tcx
>) -> Constant
<'tcx
> {
29 let Expr { ty, temp_lifetime: _, span, kind }
= expr
;
31 ExprKind
::Scope { extent: _, value }
=>
32 this
.as_constant(value
),
33 ExprKind
::Literal { literal }
=>
34 Constant { span: span, ty: ty, literal: literal }
,
38 "expression is not a valid constant {:?}",