message: Support trailing commas using ',+ ,' trick from Blandy 2017.
diff: @@ -63,4 +63,41 @@ macro_rules! doc(
  document
  }
  };
  + // if there is a trailing comma retry with the trailing comma stripped.
  + ($($field:expr => $value:expr),+ ,) => {
  + doc!( $( $field => $value ), *);
  + };
  );
  +
  +#[cfg(test)]
  +mod test {
  + use schema::{SchemaBuilder, TEXT, FAST};
  +
  + #[test]
  + fn test_doc_basic() {
  + let mut schema_builder = SchemaBuilder::new();
  + let title = schema_builder.add_text_field("title", TEXT);
  + let author = schema_builder.add_text_field("text", TEXT);
  + let likes = schema_builder.add_u64_field("num_u64", FAST);
  + let _schema = schema_builder.build();
  + let _doc = doc!(
  + title => "Life Aquatic",
  + author => "Wes Anderson",
  + likes => 4u64
  + );
  + }
  +
  + #[test]
  + fn test_doc_trailing_comma() {
  + let mut schema_builder = SchemaBuilder::new();
  + let title = schema_builder.add_text_field("title", TEXT);
  + let author = schema_builder.add_text_field("text", TEXT);
  + let likes = schema_builder.add_u64_field("num_u64", FAST);
  + let _schema = schema_builder.build();
  + let _doc = doc!(
  + title => "Life Aquatic",
  + author => "Wes Anderson",
  + likes => 4u64,
  + );
  + }
  +}
  