Use small integer repr for gen_program! enum

Remove the default __FallBack variant and Debug derive from pack types.

1 files changed, 8 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ba069e..eb30d4b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@
 1. Fixed a build failure on **Windows** caused by `mingling_core/src/program.rs`
 2. **\[picker\]** Fixed an issue where the `Pickable` trait for `Yes` and `True` types could not correctly parse explicit boolean `--value true`
 
+#### Optimizings:
+
+1. **\[macros\]** Optimized the memory usage of the `gen_program!()` macro: the internal generated enum now uses the smallest possible integer representation (`u8`, `u16`, `u32`, or `u128`) based on the number of packed types, instead of always using `u32`.
+
 #### Features:
 
 1. **\[mingling\]** Added the scaffolding tool `mling`, which can quickly deploy and test your command-line programs
@@ -164,6 +168,10 @@ let (name, age) = Picker::new(prev.inner)
     .unpack(); // will return Result<Value, Route>
 ```
 
+7. **\[macros\]** The enum generated by `gen_program!()` no longer has a default variant (`__FallBack`), and the `#[default]` attribute has been removed accordingly.
+
+8. **\[macros\]** Removed `#[derive(Debug)]` from generated pack types to remove unnecessary trait bounds.
+
 ---
 
 ### Release 0.1.6 **\[YANKED\]**