diff options
Diffstat (limited to 'src/libsyntax')
| -rw-r--r-- | src/libsyntax/ext/tt/transcribe.rs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs index 3a40e8403cc..0cefcf1ce03 100644 --- a/src/libsyntax/ext/tt/transcribe.rs +++ b/src/libsyntax/ext/tt/transcribe.rs @@ -71,7 +71,10 @@ pub fn transcribe( interp: &FxHashMap<Ident, Rc<NamedMatch>>, src: Vec<quoted::TokenTree>, ) -> TokenStream { - assert!(src.len() > 0); + // Nothing for us to transcribe... + if src.is_empty() { + return TokenStream::empty(); + } // We descend into the RHS (`src`), expanding things as we go. This stack contains the things // we have yet to expand/are still expanding. We start the stack off with the whole RHS. |