move diagnostic to new crate proc_macro2_diagnostic (#31)

Author: MusicalNinjaDad

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "try_v2"
-version = "0.3.3"
+version = "0.3.4"
 edition = "2024"
 readme = "README.md"
 description = "Provides a derive macro for `Try` ([try_trait_v2](https://rust-lang.github.io/rfcs/3058-try-trait-v2.html))"
@@ -19,6 +19,7 @@ proc-macro = true
 [dependencies]
 syn = {version = "2.0.117", features = ["full","extra-traits"]}
 proc-macro2 = "1.0.106"
+proc_macro2_diagnostic = "0.0.1"
 quote = "1.0.45"
 
 [dev-dependencies]

src/diagnostic.rs

@@ -2,7 +2,6 @@
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(never_type)]
-#![feature(proc_macro_diagnostic)]
 #![feature(try_trait_v2)]
 
 //! Provides a derive macro for `Try`
@@ -74,20 +73,17 @@
 
 use proc_macro::TokenStream as TokenStream1;
 use proc_macro2::TokenStream as TokenStream2;
+use proc_macro2_diagnostic::{
+    DiagnosticResult::{self, Ok},
+    DiagnosticStream,
+};
 use quote::{format_ident, quote};
 use syn::{
     AngleBracketedGenericArguments, Arm, Data, DataEnum, DeriveInput, Fields, GenericArgument,
     GenericParam, Ident, Lifetime, PathArguments, Type, TypePath, TypeReference, Variant,
     parse_quote, spanned::Spanned,
 };
 
-mod diagnostic;
-
-use diagnostic::{
-    DiagnosticResult::{self, Ok},
-    DiagnosticStream,
-};
-
 #[proc_macro_derive(Try)]
 /// Derives [try_trait_v2](https://rust-lang.github.io/rfcs/3058-try-trait-v2.html)
 ///