feat: adding a shorthand field option when only offset is specified

Author: WolverinDEV

raw_struct/tests/attr.rs

@@ -9,8 +9,17 @@ fn test_getter_rename() {
     struct Dummy {
         #[field(offset = 0x00, getter = "get_field_d")]
         field_a: u64,
+
+        #[field(0x08)]
+        field_b: u64,
     }
 
+    // #[raw_struct(size = 0x08, resolver = "my_dummy_function")]
+    // struct Dummy2 {
+    //     #[field(0x00)]
+    //     field_my_flag: bool,
+    // }
+
     let instance = Copy::<Dummy>::new([0x00; 0x08]);
     instance.get_field_d().unwrap();
 }

raw_struct_derive/src/derive_raw_struct.rs

@@ -8,6 +8,7 @@ use quote::{
 };
 use syn::{
     parse::{
+        discouraged::Speculative,
         Parse,
         ParseStream,
     },
@@ -52,8 +53,16 @@ struct FieldArgs {
 
 impl Parse for FieldArgs {
     fn parse(input: ParseStream) -> syn::Result<Self> {
-        let vars: Punctuated<MetaNameValue, syn::token::Comma> =
-            Punctuated::<MetaNameValue, Token![,]>::parse_terminated(input)?;
+        let fork = input.fork();
+        let Ok(vars) = fork.call(Punctuated::<MetaNameValue, Token![,]>::parse_terminated) else {
+            /* the input is already the offset value */
+            return Ok(Self {
+                offset: input.parse()?,
+                getter: None,
+                _setter: None,
+            });
+        };
+        input.advance_to(&fork);
 
         let mut offset = None;