diff --git a/src/librustc/ty/cast.rs b/src/librustc/ty/cast.rs index c118b7a4692e5..3ba79d91964ab 100644 --- a/src/librustc/ty/cast.rs +++ b/src/librustc/ty/cast.rs @@ -20,7 +20,6 @@ use syntax::ast; pub enum IntTy { U(ast::UintTy), I, - Ivar, CEnum, Bool, Char @@ -64,7 +63,7 @@ impl<'tcx> CastTy<'tcx> { ty::TyBool => Some(CastTy::Int(IntTy::Bool)), ty::TyChar => Some(CastTy::Int(IntTy::Char)), ty::TyInt(_) => Some(CastTy::Int(IntTy::I)), - ty::TyInfer(ty::InferTy::IntVar(_)) => Some(CastTy::Int(IntTy::Ivar)), + ty::TyInfer(ty::InferTy::IntVar(_)) => Some(CastTy::Int(IntTy::I)), ty::TyInfer(ty::InferTy::FloatVar(_)) => Some(CastTy::Float), ty::TyUint(u) => Some(CastTy::Int(IntTy::U(u))), ty::TyFloat(_) => Some(CastTy::Float), diff --git a/src/librustc_typeck/check/cast.rs b/src/librustc_typeck/check/cast.rs index e4bad8349ea2b..7ebacc92babf8 100644 --- a/src/librustc_typeck/check/cast.rs +++ b/src/librustc_typeck/check/cast.rs @@ -484,11 +484,7 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> { ty::TypeVariants::TyInfer(t) => { match t { ty::InferTy::IntVar(_) | - ty::InferTy::FloatVar(_) | - ty::InferTy::FreshIntTy(_) | - ty::InferTy::FreshFloatTy(_) => { - Err(CastError::NeedDeref) - } + ty::InferTy::FloatVar(_) => Err(CastError::NeedDeref), _ => Err(CastError::NeedViaPtr), } } diff --git a/src/test/run-pass/cast.rs b/src/test/run-pass/cast.rs index bb60626a4bf02..80fa5362a8be9 100644 --- a/src/test/run-pass/cast.rs +++ b/src/test/run-pass/cast.rs @@ -19,4 +19,9 @@ pub fn main() { assert_eq!(i as u8 as i8, 'Q' as u8 as i8); assert_eq!(0x51 as char, 'Q'); assert_eq!(0 as u32, false as u32); + + // Test that `_` is correctly inferred. + let x = &"hello"; + let mut y = x as *const _; + y = 0 as *const _; } diff --git a/src/test/ui/order-dependent-cast-inference.rs b/src/test/ui/order-dependent-cast-inference.rs new file mode 100644 index 0000000000000..afcd402343b25 --- /dev/null +++ b/src/test/ui/order-dependent-cast-inference.rs @@ -0,0 +1,18 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +fn main() { + // Tests case where inference fails due to the order in which casts are checked. + // Ideally this would compile, see #48270. + let x = &"hello"; + let mut y = 0 as *const _; + //~^ ERROR cannot cast to a pointer of an unknown kind + y = x as *const _; +} diff --git a/src/test/ui/order-dependent-cast-inference.stderr b/src/test/ui/order-dependent-cast-inference.stderr new file mode 100644 index 0000000000000..556acc87cffaf --- /dev/null +++ b/src/test/ui/order-dependent-cast-inference.stderr @@ -0,0 +1,13 @@ +error[E0641]: cannot cast to a pointer of an unknown kind + --> $DIR/order-dependent-cast-inference.rs:15:17 + | +LL | let mut y = 0 as *const _; + | ^^^^^-------- + | | + | help: consider giving more type information + | + = note: The type information given here is insufficient to check whether the pointer cast is valid + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0641`.