Rollup merge of #27369 - brson:realstd, r=alexcrichton

[rust.git] / src / librustc_typeck / check / cast.rs

diff --git a/src/librustc_typeck/check/cast.rs b/src/librustc_typeck/check/cast.rs
index 37541dee7d9d1c3a82bab8c0897c19bb04b30c9b..883b972872f506d24b967f6fcb692edfc812d292 100644 (file)
--- a/src/librustc_typeck/check/cast.rs
+++ b/src/librustc_typeck/check/cast.rs
@@ -122,20 +122,21 @@ fn report_cast_error<'a>(&self, fcx: &FnCtxt<'a, 'tcx>,
             CastError::NeedViaInt |
             CastError::NeedViaUsize => {
                 fcx.type_error_message(self.span, |actual| {
-                    format!("illegal cast; cast through {} first: `{}` as `{}`",
-                            match e {
-                                CastError::NeedViaPtr => "a raw pointer",
-                                CastError::NeedViaInt => "an integer",
-                                CastError::NeedViaUsize => "a usize",
-                                _ => unreachable!()
-                            },
+                    format!("casting `{}` as `{}` is invalid",
                             actual,
                             fcx.infcx().ty_to_string(self.cast_ty))
-                }, self.expr_ty, None)
+                }, self.expr_ty, None);
+                fcx.ccx.tcx.sess.fileline_help(self.span,
+                    &format!("cast through {} first", match e {
+                        CastError::NeedViaPtr => "a raw pointer",
+                        CastError::NeedViaInt => "an integer",
+                        CastError::NeedViaUsize => "a usize",
+                        _ => unreachable!()
+                }));
             }
             CastError::CastToBool => {
-                span_err!(fcx.tcx().sess, self.span, E0054,
-                          "cannot cast as `bool`, compare with zero instead");
+                span_err!(fcx.tcx().sess, self.span, E0054, "cannot cast as `bool`");
+                fcx.ccx.tcx.sess.fileline_help(self.span, "compare with zero instead");
             }
             CastError::CastToChar => {
                 fcx.type_error_message(self.span, |actual| {
@@ -151,17 +152,18 @@ fn report_cast_error<'a>(&self, fcx: &FnCtxt<'a, 'tcx>,
             }
             CastError::IllegalCast => {
                 fcx.type_error_message(self.span, |actual| {
-                    format!("illegal cast: `{}` as `{}`",
+                    format!("casting `{}` as `{}` is invalid",
                             actual,
                             fcx.infcx().ty_to_string(self.cast_ty))
                 }, self.expr_ty, None);
             }
             CastError::DifferingKinds => {
                 fcx.type_error_message(self.span, |actual| {
-                    format!("illegal cast: `{}` as `{}`; vtable kinds may not match",
+                    format!("casting `{}` as `{}` is invalid",
                             actual,
                             fcx.infcx().ty_to_string(self.cast_ty))
                 }, self.expr_ty, None);
+                fcx.ccx.tcx.sess.fileline_note(self.span, "vtable kinds may not match");
             }
         }
     }
@@ -285,7 +287,7 @@ fn check_ptr_ptr_cast<'a>(&self,
             return Ok(CastKind::PtrPtrCast);
         }
 
-        // sized -> unsized? report illegal cast (don't complain about vtable kinds)
+        // sized -> unsized? report invalid cast (don't complain about vtable kinds)
         if fcx.type_is_known_to_be_sized(m_expr.ty, self.span) {
             return Err(CastError::IllegalCast);
         }