refactoring: re-export custom derive with additional items (WIP)

derive_builder_core/src/bindings.rs

@@ -23,13 +23,23 @@ impl Bindings {
             Bindings::NoStd => ":: collections :: string :: String",
         })
     }
+
+    /// TryInto trait. Once `TryFrom` stabilizes, this should be removed and
+    /// `derive_builder::export` should export `core::convert::TryInto` directly.
+    pub fn try_into_trait(&self) -> RawTokens<&'static str> {
+        RawTokens(match *self {
+            Bindings::Std => ":: std :: convert :: TryInto",
+            Bindings::NoStd => ":: core :: convert :: TryInto",
+        })
+    }
 }
 
 #[test]
 fn std() {
     let b = Bindings::Std;
 
     assert_eq!(b.string_ty().to_tokens(), quote!(::std::string::String));
+    assert_eq!(b.try_into_trait().to_tokens(), quote!(::std::convert::TryInto));
 }
 
 #[test]
@@ -38,4 +48,5 @@ fn no_std() {
 
     assert_eq!(b.string_ty().to_tokens(),
                quote!(::collections::string::String));
+    assert_eq!(b.try_into_trait().to_tokens(), quote!(::core::convert::TryInto));
 }

derive_builder_core/src/setter.rs

@@ -119,7 +119,8 @@ impl<'a> ToTokens for Setter<'a> {
             }));
 
             if self.try_setter {
-                let try_ty_params = quote!(<VALUE: ::derive_builder::export::TryInto<#ty>>);
+                let try_into_trait = self.bindings.try_into_trait();
+                let try_ty_params = quote!(<VALUE: #try_into_trait<#ty>>);
                 let try_ident = syn::Ident::new(format!("try_{}", ident));
 
                 tokens.append(quote!(
@@ -264,7 +265,7 @@ mod tests {
             }
 
             #[some_attr]
-            pub fn try_foo<VALUE: ::derive_builder::export::TryInto<Foo>>(&mut self, value: VALUE)
+            pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE)
                 -> ::derive_builder::export::Result<&mut Self, VALUE::Error> {
                 let converted : Foo = value.try_into()?;
                 let mut new = self;
@@ -325,7 +326,7 @@ mod tests {
                 new
             }
 
-            pub fn try_foo<VALUE: ::derive_builder::export::TryInto<Foo>>(&mut self, value: VALUE)
+            pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE)
                 -> ::derive_builder::export::Result<&mut Self, VALUE::Error> {
                 let converted : Foo = value.try_into()?;
                 let mut new = self;