Remove another old workaround

Author: sfackler

src/types/slice.rs

@@ -2,7 +2,6 @@ use std::io::prelude::*;
 use byteorder::{WriteBytesExt, BigEndian};
 
 use Result;
-use error::Error;
 use types::{Type, ToSql, Kind, IsNull, SessionInfo, downcast};
 
 /// An adapter type mapping slices to Postgres arrays.
@@ -30,14 +29,6 @@ use types::{Type, ToSql, Kind, IsNull, SessionInfo, downcast};
 pub struct Slice<'a, T: 'a + ToSql>(pub &'a [T]);
 
 impl<'a, T: 'a + ToSql> ToSql for Slice<'a, T> {
-    // FIXME should use to_sql_checked!() but blocked on rust-lang/rust#24308
-    fn to_sql_checked(&self, ty: &Type, out: &mut Write, ctx: &SessionInfo) -> Result<IsNull> {
-        if !<Slice<'a, T> as ToSql>::accepts(ty) {
-            return Err(Error::WrongType(ty.clone()));
-        }
-        self.to_sql(ty, out, ctx)
-    }
-
     fn to_sql<W: Write + ?Sized>(&self,
                                  ty: &Type,
                                  mut w: &mut W,
@@ -76,4 +67,6 @@ impl<'a, T: 'a + ToSql> ToSql for Slice<'a, T> {
             _ => false,
         }
     }
+
+    to_sql_checked!();
 }