Add missing where clause forwarding to #[builder(derive(Into))]

bon-macros/src/builder/builder_gen/builder_derives/into.rs

@@ -41,6 +41,7 @@ impl BuilderGenCtx {
         let state_mod = &self.state_mod.ident;
         let generics_decl = &self.generics.decl_without_defaults;
         let generic_args = &self.generics.args;
+        let where_clause = &self.generics.where_clause;
         let builder_ident = &self.builder_type.ident;
         let state_var = &self.state_var;
         let finish_fn_ident = &self.finish_fn.ident;
@@ -55,7 +56,9 @@ impl BuilderGenCtx {
                 #(#generics_decl,)*
                 #state_var: #state_mod::IsComplete
             >
-            ::core::convert::From<#builder_ty> for #output_ty {
+            ::core::convert::From<#builder_ty> for #output_ty
+            #where_clause
+            {
                 fn from(builder: #builder_ty) -> Self {
                     #builder_ident::#finish_fn_ident(builder)
                 }

bon/tests/integration/builder/attr_derive.rs

@@ -148,7 +148,10 @@ mod generics {
     fn test_struct() {
         #[derive(Builder, Debug)]
         #[builder(derive(Clone, Debug, Into))]
-        struct Sut<T> {
+        struct Sut<T>
+        where
+            T: Clone,
+        {
             _arg1: T,
         }
 
@@ -164,7 +167,10 @@ mod generics {
     #[test]
     fn test_function() {
         #[builder(derive(Clone, Debug, Into))]
-        fn sut<T>(_arg1: T) -> u32 {
+        fn sut<T>(_arg1: T) -> u32
+        where
+            T: Clone,
+        {
             99
         }
 
@@ -183,7 +189,10 @@ mod generics {
         struct Sut<T>(T);
 
         #[bon]
-        impl<T> Sut<T> {
+        impl<T> Sut<T>
+        where
+            T: Clone,
+        {
             #[builder(derive(Clone, Debug, Into))]
             fn sut<U>(_arg1: U) -> u32 {
                 99