add trybuild test output

Author: cosmicexplorer

num_enum/tests/try_build/compile_fail/custom_method_name_parsing.rs

@@ -0,0 +1,39 @@
+#[derive(num_enum::ConstTryFromPrimitive)]
+#[num_enum(method_names(const_try = f))]
+#[repr(u8)]
+enum MissingConstructor {
+    Zero,
+    One,
+    Two,
+}
+
+#[derive(num_enum::ConstTryFromPrimitive)]
+#[num_enum(method_names(const_try_from = f, extra = something))]
+#[repr(u8)]
+enum MissingConstructor1 {
+    Zero,
+    One,
+    Two,
+}
+
+#[derive(num_enum::ConstTryFromPrimitive)]
+#[num_enum(method_names(const_try_from = f, const_into = g, const_try_from = something))]
+#[repr(u8)]
+enum MissingConstructor2 {
+    Zero,
+    One,
+    Two,
+}
+
+#[derive(num_enum::ConstTryFromPrimitive)]
+#[num_enum(method_names(const_try_from = f, const_into = g))]
+#[num_enum(method_names(const_try_from = f1, const_into = g1))]
+#[repr(u8)]
+enum MissingConstructor3 {
+    Zero,
+    One,
+    Two,
+}
+
+fn main() {
+}

num_enum/tests/try_build/compile_fail/custom_method_name_parsing.stderr

@@ -0,0 +1,23 @@
+error: expected one of: `const_into`, `const_from`, `const_try_from`, `const_default`
+ --> tests/try_build/compile_fail/custom_method_name_parsing.rs:2:25
+  |
+2 | #[num_enum(method_names(const_try = f))]
+  |                         ^^^^^^^^^
+
+error: expected one of: `const_into`, `const_from`, `const_try_from`, `const_default`
+  --> tests/try_build/compile_fail/custom_method_name_parsing.rs:11:45
+   |
+11 | #[num_enum(method_names(const_try_from = f, extra = something))]
+   |                                             ^^^^^
+
+error: At most one num_enum const_try_from method name may be specified
+  --> tests/try_build/compile_fail/custom_method_name_parsing.rs:20:61
+   |
+20 | #[num_enum(method_names(const_try_from = f, const_into = g, const_try_from = something))]
+   |                                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: At most one num_enum method_names attribute may be specified
+  --> tests/try_build/compile_fail/custom_method_name_parsing.rs:30:1
+   |
+30 | #[num_enum(method_names(const_try_from = f1, const_into = g1))]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

num_enum_derive/src/enum_attributes.rs

@@ -1,5 +1,4 @@
 use crate::utils::die;
-use core::marker::PhantomData;
 use proc_macro2::{Span, TokenStream};
 use quote::ToTokens;
 use syn::{
@@ -253,30 +252,23 @@ impl Parse for GeneratedMethodNameArgument {
 #[derive(Clone)]
 #[cfg_attr(test, derive(Debug))]
 pub(crate) struct GeneratedMethodNameAttribute<KW> {
+    pub(crate) kw: KW,
     pub(crate) id: syn::Ident,
-    _ph: PhantomData<KW>,
-}
-
-impl<KW> GeneratedMethodNameAttribute<KW> {
-    pub(crate) fn new(id: syn::Ident) -> Self {
-        Self {
-            id,
-            _ph: PhantomData,
-        }
-    }
 }
 
 impl<KW: Parse> Parse for GeneratedMethodNameAttribute<KW> {
     fn parse(input: ParseStream) -> Result<Self> {
-        input.parse::<KW>()?;
+        let kw = input.parse::<KW>()?;
         input.parse::<syn::Token![=]>()?;
         let id = input.parse()?;
-        Ok(Self::new(id))
+
+        Ok(Self { kw, id })
     }
 }
 
-impl<KW> ToTokens for GeneratedMethodNameAttribute<KW> {
+impl<KW: ToTokens> ToTokens for GeneratedMethodNameAttribute<KW> {
     fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.kw.to_tokens(tokens);
         self.id.to_tokens(tokens);
     }
 }