fix(zkvms_host_io/input_macros): Add comma on public_types count

The `sep` variable is used below, in `output_type`, where the public
types are laid out. Before, we checked the count of all types, including
private ones, which caused a crash when we have no private inputs.

1 files changed, 1 insertions, 1 deletions

diff --git a/zkvms_host_io/input_macros/src/lib.rs b/zkvms_host_io/input_macros/src/lib.rs
index e66a0a4..448f76e 100644
--- a/zkvms_host_io/input_macros/src/lib.rs
+++ b/zkvms_host_io/input_macros/src/lib.rs
@@ -66,7 +66,7 @@ static DERIVES: &str = "#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deseria
 pub fn generate_output_type_input_struct(_: TokenStream) -> TokenStream {
     let fd = new_fd();
 
-    let sep = if fd.types().is_empty() { "" } else { ", " };
+    let sep = if fd.public_types().is_empty() { "" } else { ", " };
     let output_type = format!("pub type Output = ({} {} {});", fd.grouped_public_types(), sep, fd.return_type).to_string();
 
     let return_type = format!("pub type Return = {};", fd.return_type).to_string();