From f989e466aa63c0e65e396b2db3e6cfe7cb003e33 Mon Sep 17 00:00:00 2001
From: Artem Romanenia <artem.romanenia@gmail.com>
Date: Mon, 5 Aug 2024 13:00:57 +0300
Subject: [PATCH] Support no_std stage 2

---
 Cargo.toml             | 8 ++++++--
 o2o-impl/src/expand.rs | 7 ++-----
 src/lib.rs             | 6 ++----
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 25e2dca..964c420 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,8 +10,12 @@ license = "MIT OR Apache-2.0"
 repository = "https://github.com/Artem-Romanenia/o2o"
 
 [dependencies]
-o2o-impl = { version = "0.4.9-alpha.1", path = "o2o-impl" }
-o2o-macros = { version = "0.4.9-alpha.1", path = "o2o-macros" }
+o2o-impl = { version = "0.4.9-alpha.1", path = "o2o-impl", optional = true }
+o2o-macros = { version = "0.4.9-alpha.1", path = "o2o-macros", optional = true }
+
+[features]
+default = ["macro"]
+macro = ["dep:o2o-impl", "dep:o2o-macros"]
 
 [workspace]
 members = ["o2o-impl", "o2o-macros", "o2o-tests"]
diff --git a/o2o-impl/src/expand.rs b/o2o-impl/src/expand.rs
index bbe91ac..bd93fd4 100644
--- a/o2o-impl/src/expand.rs
+++ b/o2o-impl/src/expand.rs
@@ -22,10 +22,7 @@ pub fn derive(node: &DeriveInput) -> Result<TokenStream> {
             validate(&input)?;
             Ok(data_type_impl(input))
         },
-        _ => Err(Error::new_spanned(
-            node,
-            "#[derive(o2o)] only supports structs and enums.",
-        ))
+        _ => Err(Error::new_spanned(node, "#[derive(o2o)] only supports structs and enums."))
     }
 }
 
@@ -384,7 +381,7 @@ fn struct_init_block<'a>(input: &'a Struct, ctx: &ImplContext) -> TokenStream {
             unique_paths.insert(path);
             make_tuple(path, FieldData::Field(x))
         }).collect::<Vec<(usize, &str, FieldData)>>());
-    
+
     fields.extend(input.attrs.ghosts_attrs.iter()
         .flat_map(|x| &x.attr.ghost_data)
         .filter(|x| unique_paths.insert(x.get_child_path_str(None)))
diff --git a/src/lib.rs b/src/lib.rs
index b816f64..54da9ae 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,8 +1,6 @@
 #![doc = include_str!("../README.md")]
 
-extern crate o2o_impl;
-extern crate o2o_macros;
+#[cfg(feature = "macro")]
+pub use o2o_macros::*;
 
 pub mod traits;
-
-pub use o2o_macros::*;
\ No newline at end of file