tests/rustdoc-json/fns/pattern_arg.rs

//@ is "$.index[?(@.name=='fst')].inner.function.sig.inputs[0][0]" '"(x, _)"'
pub fn fst<X, Y>((x, _): (X, Y)) -> X {
    x
}

//@ is "$.index[?(@.name=='drop_int')].inner.function.sig.inputs[0][0]" '"_"'
pub fn drop_int(_: i32) {}