macro_rules! opt_field_struct {
    (
        $(#[$attr:meta])*
        $visibility:vis struct $struct_name:ident {
            $(
                $(#[$field_attr:meta])*
                $field_visibility:vis $field_name:ident: $field_ty:ty,
            )*
        }
    ) => {
        $(#[$attr])*
        $visibility struct $struct_name {
            $(
                $(#[$field_attr])*
                $field_visibility $field_name: $field_ty,
            )*
        }

        impl $struct_name {
            $visibility fn is_complete(&self) -> bool {
                $(
                    if self.$field_name.is_none() {
                        return false
                    }
                )*


                true
            }
        }
    };
}

opt_field_struct!(
    struct MyStruct {
        pub optional_field: Option<usize>,
        another_optional_field: Option<String>,
        and_another: Option<String>,
    }
);

// Generated code:
struct MyStruct {
    pub optional_field: Option<usize>,
    another_optional_field: Option<String>,
    and_another: Option<String>,
}
impl MyStruct {
    fn is_complete(&self) -> bool {
        if self.optional_field.is_none() {
            return false;
        }
        if self.another_optional_field.is_none() {
            return false;
        }
        if self.and_another.is_none() {
            return false;
        }
        true
    }
}