Function syntax::ext::base::check_zero_tts

pub fn check_zero_tts(cx: &ExtCtxt, sp: Span, tts: &[TokenTree], name: &str)

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Non-fatally assert that tts is empty. Note that this function returns even when tts is non-empty, macros that need to stop compilation should call cx.parse_sess.span_diagnostic.abort_if_errors() (this should be done as rarely as possible).