From ec3297242c75a5d47945eeff0dc2ebef09eb7e9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Peter=20Glotfelty=20=F0=9F=9A=80?= <peglotfe@microsoft.com>
Date: Sun, 26 Jul 2020 04:41:15 +0000
Subject: [PATCH] Replaced const fn count with associated constant.

---
 strum/src/lib.rs                      |  8 ++++----
 strum_macros/src/macros/enum_count.rs | 19 +++++--------------
 strum_tests/tests/enum_count.rs       |  5 ++---
 3 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/strum/src/lib.rs b/strum/src/lib.rs
index 4623eb2..0f00094 100644
--- a/strum/src/lib.rs
+++ b/strum/src/lib.rs
@@ -192,12 +192,12 @@ pub trait EnumMessage {
 /// }
 /// ```
 pub trait EnumProperty {
-    fn get_str(&self, &str) -> Option<&'static str>;
-    fn get_int(&self, &str) -> Option<usize> {
+    fn get_str(&self, prop: &str) -> Option<&'static str>;
+    fn get_int(&self, _prop: &str) -> Option<usize> {
         Option::None
     }
 
-    fn get_bool(&self, &str) -> Option<bool> {
+    fn get_bool(&self, _prop: &str) -> Option<bool> {
         Option::None
     }
 }
@@ -215,7 +215,7 @@ where
 /// A trait for capturing the number of variants in Enum. This trait can be autoderived by
 /// `strum_macros`.
 pub trait EnumCount {
-    fn count() -> usize;
+    const COUNT: usize;
 }
 
 /// A trait for retrieving the names of each variant in Enum. This trait can
diff --git a/strum_macros/src/macros/enum_count.rs b/strum_macros/src/macros/enum_count.rs
index c22cfa5..0a26b62 100644
--- a/strum_macros/src/macros/enum_count.rs
+++ b/strum_macros/src/macros/enum_count.rs
@@ -1,4 +1,4 @@
-use proc_macro2::{Span, TokenStream};
+use proc_macro2::TokenStream;
 use syn;
 
 pub(crate) fn enum_count_inner(ast: &syn::DeriveInput) -> TokenStream {
@@ -9,23 +9,14 @@ pub(crate) fn enum_count_inner(ast: &syn::DeriveInput) -> TokenStream {
 
     // Used in the quasi-quotation below as `#name`
     let name = &ast.ident;
-    let const_name = &syn::Ident::new(
-        &format!("{}_COUNT", name.to_string().to_uppercase()),
-        Span::call_site(),
-    );
 
     // Helper is provided for handling complex generic types correctly and effortlessly
     let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
 
     quote! {
-            // Implementation
-            impl #impl_generics ::strum::EnumCount for #name #ty_generics #where_clause {
-                fn count() -> usize {
-                    #n
-                }
-            }
-
-            #[allow(dead_code, missing_docs)]
-            pub const #const_name: usize = #n;
+        // Implementation
+        impl #impl_generics ::strum::EnumCount for #name #ty_generics #where_clause {
+            const COUNT: usize = #n;
+        }
     }
 }
diff --git a/strum_tests/tests/enum_count.rs b/strum_tests/tests/enum_count.rs
index bdb5b74..895fab6 100644
--- a/strum_tests/tests/enum_count.rs
+++ b/strum_tests/tests/enum_count.rs
@@ -17,7 +17,6 @@ enum Week {
 
 #[test]
 fn simple_test() {
-    assert_eq!(7, Week::count());
-    assert_eq!(Week::count(), WEEK_COUNT);
-    assert_eq!(Week::iter().count(), WEEK_COUNT);
+    assert_eq!(7, Week::COUNT);
+    assert_eq!(Week::iter().count(), Week::COUNT);
 }