commit 577135e79a32ccb927dc958e2225c69bc0238772
author David Tolnay <dtolnay@gmail.com> Fri Nov 27 16:23:53 2020 -0800
committer David Tolnay <dtolnay@gmail.com> Fri Nov 27 17:17:51 2020 -0800
tree 7eef59f78afe9de902ef442657546f8b850a8276
parent bb6898536c42c9255fbcc4efdc6caf36d4349203

Support derive(PartialOrd, Ord)

macro/src/derive.rs

diff --git a/macro/src/derive.rs b/macro/src/derive.rs
index 28dfae3..91a5d9d 100644
--- a/macro/src/derive.rs
+++ b/macro/src/derive.rs
@@ -15,7 +15,9 @@
             Trait::Clone => expanded.extend(struct_clone(strct, span)),
             Trait::Debug => expanded.extend(struct_debug(strct, span)),
             Trait::Eq => traits.push(quote_spanned!(span=> ::std::cmp::Eq)),
+            Trait::Ord => expanded.extend(struct_ord(strct, span)),
             Trait::PartialEq => traits.push(quote_spanned!(span=> ::std::cmp::PartialEq)),
+            Trait::PartialOrd => expanded.extend(struct_partial_ord(strct, span)),
         }
     }
 
@@ -52,10 +54,12 @@
                 traits.push(quote_spanned!(span=> ::std::cmp::Eq));
                 has_eq = true;
             }
+            Trait::Ord => expanded.extend(enum_ord(enm, span)),
             Trait::PartialEq => {
                 traits.push(quote_spanned!(span=> ::std::cmp::PartialEq));
                 has_partial_eq = true;
             }
+            Trait::PartialOrd => expanded.extend(enum_partial_ord(enm, span)),
         }
     }
 
@@ -132,6 +136,54 @@
     }
 }
 
+fn struct_ord(strct: &Struct, span: Span) -> TokenStream {
+    let ident = &strct.name.rust;
+    let fields = strct.fields.iter().map(|field| &field.ident);
+
+    quote_spanned! {span=>
+        impl ::std::cmp::Ord for #ident {
+            fn cmp(&self, other: &Self) -> ::std::cmp::Ordering {
+                #(
+                    match ::std::cmp::Ord::cmp(&self.#fields, &other.#fields) {
+                        ::std::cmp::Ordering::Equal => {}
+                        ordering => return ordering,
+                    }
+                )*
+                ::std::cmp::Ordering::Equal
+            }
+        }
+    }
+}
+
+fn struct_partial_ord(strct: &Struct, span: Span) -> TokenStream {
+    let ident = &strct.name.rust;
+
+    let body = if derive::contains(&strct.derives, Trait::Ord) {
+        quote! {
+            ::std::option::Option::Some(::std::cmp::Ord::cmp(self, other))
+        }
+    } else {
+        let fields = strct.fields.iter().map(|field| &field.ident);
+        quote! {
+            #(
+                match ::std::cmp::PartialOrd::partial_cmp(&self.#fields, &other.#fields) {
+                    ::std::option::Option::Some(::std::cmp::Ordering::Equal) => {}
+                    ordering => return ordering,
+                }
+            )*
+            ::std::option::Option::Some(::std::cmp::Ordering::Equal)
+        }
+    };
+
+    quote_spanned! {span=>
+        impl ::std::cmp::PartialOrd for #ident {
+            fn partial_cmp(&self, other: &Self) -> ::std::option::Option<::std::cmp::Ordering> {
+                #body
+            }
+        }
+    }
+}
+
 fn enum_copy(enm: &Enum, span: Span) -> TokenStream {
     let ident = &enm.name.rust;
 
@@ -174,3 +226,27 @@
         }
     }
 }
+
+fn enum_ord(enm: &Enum, span: Span) -> TokenStream {
+    let ident = &enm.name.rust;
+
+    quote_spanned! {span=>
+        impl ::std::cmp::Ord for #ident {
+            pub fn cmp(&self, other: &Self) -> ::std::cmp::Ordering {
+                ::std::cmp::Ord::cmp(&self.repr, &other.repr)
+            }
+        }
+    }
+}
+
+fn enum_partial_ord(enm: &Enum, span: Span) -> TokenStream {
+    let ident = &enm.name.rust;
+
+    quote_spanned! {span=>
+        impl ::std::cmp::PartialOrd for #ident {
+            pub fn cmp(&self, other: &Self) -> ::std::option::Option<::std::cmp::Ordering> {
+                ::std::cmp::PartialOrd::cmp(&self.repr, &other.repr)
+            }
+        }
+    }
+}

syntax/derive.rs

diff --git a/syntax/derive.rs b/syntax/derive.rs
index d258cc7..1099967 100644
--- a/syntax/derive.rs
+++ b/syntax/derive.rs
@@ -12,7 +12,9 @@
     Copy,
     Debug,
     Eq,
+    Ord,
     PartialEq,
+    PartialOrd,
 }
 
 impl Derive {
@@ -22,7 +24,9 @@
             "Copy" => Trait::Copy,
             "Debug" => Trait::Debug,
             "Eq" => Trait::Eq,
+            "Ord" => Trait::Ord,
             "PartialEq" => Trait::PartialEq,
+            "PartialOrd" => Trait::PartialOrd,
             _ => return None,
         };
         let span = ident.span();

tests/ffi/lib.rs

diff --git a/tests/ffi/lib.rs b/tests/ffi/lib.rs
index 021b0c3..cb0f916 100644
--- a/tests/ffi/lib.rs
+++ b/tests/ffi/lib.rs
@@ -15,12 +15,12 @@
 
 #[cxx::bridge(namespace = "tests")]
 pub mod ffi {
-    #[derive(Clone, Debug, PartialEq, Eq)]
+    #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
     struct Shared {
         z: usize,
     }
 
-    #[derive(PartialEq)]
+    #[derive(PartialEq, PartialOrd)]
     struct SharedString {
         msg: String,
     }