Use ? instead of try

src/util.rs

@@ -27,9 +27,9 @@ use result::*;
 
 /// try! get smbc function or return io::Error(EINVAL)
 macro_rules! try_ufn {
-    ($e:ident <- $s:expr) => (try!(unsafe {
+    ($e:ident <- $s:expr) => (unsafe {
         $e($s.ctx).ok_or($crate::std::io::Error::from_raw_os_error(libc::EINVAL as i32))
-    }))
+    }?)
 }
 
 #[inline(always)]
@@ -49,7 +49,7 @@ pub unsafe fn cstr<'a, T>(p: *const T) -> Cow<'a, str> {
 }
 
 pub fn cstring<P: AsRef<str>>(p: P) -> Result<CString> {
-    Ok(try!(CString::new(p.as_ref())))
+    Ok(CString::new(p.as_ref())?)
 }
 
 pub unsafe fn write_to_cstr(dest: *mut u8, len: usize, src: &str) {