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improve comments on safe_to_unsafe_fn_ty and coerce_closure_fn_ty

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This commit is contained in:
Niko Matsakis 2017-12-12 14:21:10 -05:00
parent 7a20a3f161
commit f6723a9592
1 changed files with 9 additions and 4 deletions
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13
src/librustc/ty/context.rs
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@ -1708,7 +1708,9 @@ slice_interners!(
);
impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
/// Create an unsafe fn ty based on a safe fn ty.
/// Given a `fn` type, returns an equivalent `unsafe fn` type;
/// that is, a `fn` type that is equivalent in every way for being
/// unsafe.
pub fn safe_to_unsafe_fn_ty(self, sig: PolyFnSig<'tcx>) -> Ty<'tcx> {
assert_eq!(sig.unsafety(), hir::Unsafety::Normal);
self.mk_fn_ptr(sig.map_bound(|sig| ty::FnSig {
@ -1717,7 +1719,10 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
}))
}
/// Create an unsafe fn ty based on a safe fn ty.
/// Given a closure signature `sig`, returns an equivalent `fn`
/// type with the same signature. Detuples and so forth -- so
/// e.g. if we have a sig with `Fn<(u32, i32)>` then you would get
/// a `fn(u32, i32)`.
pub fn coerce_closure_fn_ty(self, sig: PolyFnSig<'tcx>) -> Ty<'tcx> {
let converted_sig = sig.map_bound(|s| {
let params_iter = match s.inputs()[0].sty {
@ -1731,8 +1736,8 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
s.output(),
s.variadic,
hir::Unsafety::Normal,
abi::Abi::Rust
)
abi::Abi::Rust,
)
});
self.mk_fn_ptr(converted_sig)