From 71e2c05adec185d2a592d0733a133124cf37e83c Mon Sep 17 00:00:00 2001
From: Guillaume Pinot <texitoi@texitoi.eu>
Date: Tue, 27 Mar 2018 09:44:36 +0200
Subject: [PATCH] Fix compilation with `#[deny(warnings)]` with the `!` type

https://github.com/rust-lang/rust/pull/49039#issuecomment-376420816
---
 .travis.yml                 |  4 +---
 CHANGELOG.md                |  4 +++-
 Cargo.toml                  |  2 +-
 structopt-derive/Cargo.toml |  2 +-
 structopt-derive/src/lib.rs |  4 ++--
 tests/deny-warnings.rs      | 46 +++++++++++++++++++++++++++++++++++++
 6 files changed, 54 insertions(+), 8 deletions(-)
 create mode 100644 tests/deny-warnings.rs

diff --git a/.travis.yml b/.travis.yml
index 11a38d41..982b0bb6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,9 +7,7 @@ rust:
 matrix:
   include:
     - rust: nightly
-      env: FEATURES="--features testing_only_proc_macro2_nightly"
-  allow_failures:
-    - rust: nightly
+      env: FEATURES="--features nightly"
 
 script:
   - cargo test $FEATURES
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b98fc16f..fba7fe89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,6 @@
-# v0.2.5 (2018-XX-XX)
+# v0.2.6 (2018-XX-XX)
+
+* Fix compilation with `#[deny(warnings)]` with the `!` type (https://github.com/rust-lang/rust/pull/49039#issuecomment-376420816) by [@TeXitoi](https://github.com/TeXitoi)
 
 * Improve first example in the documentation ([#82](https://github.com/TeXitoi/structopt/issues/82)) by [@TeXitoi](https://github.com/TeXitoi)
 
diff --git a/Cargo.toml b/Cargo.toml
index 2fe0abf3..adb8d5c1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ readme = "README.md"
 
 [features]
 default = ["clap/default"]
-testing_only_proc_macro2_nightly = ["structopt-derive/testing_only_proc_macro2_nightly"]
+nightly = ["structopt-derive/nightly"]
 
 [badges]
 travis-ci = { repository = "TeXitoi/structopt" }
diff --git a/structopt-derive/Cargo.toml b/structopt-derive/Cargo.toml
index da134629..7bc3fb33 100644
--- a/structopt-derive/Cargo.toml
+++ b/structopt-derive/Cargo.toml
@@ -18,7 +18,7 @@ quote = "0.4"
 proc-macro2 = "0.2"
 
 [features]
-testing_only_proc_macro2_nightly = ["proc-macro2/nightly"]
+nightly = ["proc-macro2/nightly"]
 
 [lib]
 proc-macro = true
diff --git a/structopt-derive/src/lib.rs b/structopt-derive/src/lib.rs
index fb7bce25..b38c4c0a 100644
--- a/structopt-derive/src/lib.rs
+++ b/structopt-derive/src/lib.rs
@@ -381,7 +381,7 @@ fn impl_structopt_for_struct(
             #from_clap
         }
 
-        #[allow(dead_code)]
+        #[allow(dead_code, unreachable_code)]
         #[doc(hidden)]
         impl #name {
             #augment_clap
@@ -406,7 +406,7 @@ fn impl_structopt_for_enum(
             #from_clap
         }
 
-        #[allow(unused_variables, dead_code)]
+        #[allow(unused_variables, dead_code, unreachable_code)]
         #[doc(hidden)]
         impl #name {
             #augment_clap
diff --git a/tests/deny-warnings.rs b/tests/deny-warnings.rs
new file mode 100644
index 00000000..2dde87da
--- /dev/null
+++ b/tests/deny-warnings.rs
@@ -0,0 +1,46 @@
+// Copyright 2018 Guillaume Pinot (@TeXitoi) <texitoi@texitoi.eu>
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(warnings)]
+#![cfg(feature = "nightly")]// TODO: remove that when never is stable
+
+#[macro_use]
+extern crate structopt;
+
+use structopt::StructOpt;
+
+fn try_str(s: &str) -> Result<String, !> {
+    Ok(s.into())
+}
+
+#[test]
+fn warning_never_struct() {
+    #[derive(Debug, PartialEq, StructOpt)]
+    struct Opt {
+        #[structopt(parse(try_from_str = "try_str"))]
+        s: String,
+    }
+    assert_eq!(Opt { s: "foo".to_string() },
+               Opt::from_iter(&["test", "foo"]));
+
+}
+
+#[test]
+fn warning_never_enum() {
+    #[derive(Debug, PartialEq, StructOpt)]
+    enum Opt {
+        Foo {
+            #[structopt(parse(try_from_str = "try_str"))]
+            s: String,
+        }
+    }
+    assert_eq!(Opt::Foo { s: "foo".to_string() },
+               Opt::from_iter(&["test", "Foo", "foo"]));
+
+}
+