scraped together some msrv compatibility

Author: ModProg

src/attr/item.rs

@@ -11,7 +11,7 @@ use syn::{
 	TraitBoundModifier, Type, TypeParamBound, TypePath, WhereClause, WherePredicate,
 };
 
-use crate::{util, Error, Item, Skip, Trait, TraitImpl, DERIVE_WHERE};
+use crate::{DERIVE_WHERE, DERIVE_WHERE_INTERNAL, Error, Item, Skip, Trait, TraitImpl, util};
 
 /// Attributes on item.
 #[derive(Default)]
@@ -29,7 +29,7 @@ impl ItemAttr {
 		let mut skip_inners = Vec::new();
 
 		for attr in attrs {
-			if attr.path.is_ident(DERIVE_WHERE) {
+			if attr.path.is_ident(DERIVE_WHERE) || attr.path.is_ident(DERIVE_WHERE_INTERNAL) {
 				if let Ok(meta) = attr.parse_meta() {
 					if let Meta::List(list) = meta {
 						match list.nested.len() {

src/lib.rs

@@ -334,6 +334,8 @@ use self::{
 
 /// Token used for attributes.
 const DERIVE_WHERE: &str = "derive_where";
+/// Token used for attributes internaly.
+const DERIVE_WHERE_INTERNAL: &str = "__derive_where_internal_derive_attr";
 
 /// derive_where attribute macro, that does not require deriving
 #[proc_macro_attribute]
@@ -343,12 +345,12 @@ pub fn derive_where(
 ) -> proc_macro::TokenStream {
 	let attr: TokenStream = attr.into();
 	let input: TokenStream = input.into();
-	quote! {
+	let output = quote! {
 		#[derive(::derive_where::DeriveWhere)]
-		#[derive_where(#attr)]
+		#[__derive_where_internal_derive_attr(#attr)]
 		#input
-	}
-	.into()
+	};
+	output.into()
 }
 
 /// Item-level options:
@@ -376,7 +378,7 @@ pub fn derive_where(
 /// See the [crate](crate) level description for more details.
 ///
 /// [`Zeroize`]: https://docs.rs/zeroize/latest/zeroize/trait.Zeroize.html
-#[proc_macro_derive(DeriveWhere, attributes(derive_where))]
+#[proc_macro_derive(DeriveWhere, attributes(derive_where,__derive_where_internal_derive_attr))]
 #[cfg_attr(feature = "nightly", allow_internal_unstable(core_intrinsics))]
 pub fn derive_where_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 	match derive_where_internal(input.into()) {

tests/bound.rs

@@ -2,7 +2,7 @@ mod util;
 
 use std::marker::PhantomData;
 
-use derive_where::{derive_where, DeriveWhere};
+use derive_where::derive_where;
 
 use self::util::AssertClone;
 
@@ -18,7 +18,6 @@ fn custom_generic() {
 		type Type = i32;
 	}
 
-	#[derive(DeriveWhere)]
 	#[derive_where(Clone; T::Type)]
 	struct Test<T: Trait>(T::Type);
 

tests/enum_mixed.rs

@@ -5,17 +5,17 @@ mod util;
 
 use std::cmp::Ordering;
 
-use derive_where::DeriveWhere;
-
 use self::util::{
 	AssertClone, AssertCopy, AssertDebug, AssertEq, AssertHash, AssertOrd, AssertPartialEq,
 	AssertPartialOrd, Wrapper,
 };
 
 #[test]
 fn all() {
-	#[derive(DeriveWhere)]
-	#[derive_where(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
+	// #[derive(DeriveWhere)]
+    use derive_where::derive_where as dw_macro;
+	#[dw_macro(Clone, Copy, Debug)]
+    #[derive_where(Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
 	enum Test<T> {
 		#[derive_where(default)]
 		A {