From 781977a23751c6a9ec07a387fc54c32cf5190e47 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Mon, 29 May 2017 21:38:04 +0300
Subject: [PATCH] Add test/get_by_index.cpp

---
 include/boost/variant2/variant.hpp |  44 +------
 test/Jamfile                       |   1 +
 test/get_by_index.cpp              | 184 +++++++++++++++++++++++++++++
 3 files changed, 189 insertions(+), 40 deletions(-)
 create mode 100644 test/get_by_index.cpp

diff --git a/include/boost/variant2/variant.hpp b/include/boost/variant2/variant.hpp
index 29991c1..28079b6 100644
--- a/include/boost/variant2/variant.hpp
+++ b/include/boost/variant2/variant.hpp
@@ -114,61 +114,25 @@ template<class U, class... T> constexpr bool holds_alternative( variant<T...> co
 template<std::size_t I, class... T> constexpr variant_alternative_t<I, variant<T...>>& get(variant<T...>& v)
 {
     static_assert( I < sizeof...(T), "Index out of bounds" );
-
-#if BOOST_WORKAROUND( BOOST_MSVC, <= 1910 )
-
-    return v.index() == I? v._get_impl( mp_size_t<I>() ): ( throw bad_variant_access(), v._get_impl( mp_size_t<I>() ) );
-
-#else
-
-    return v.index() == I? v._get_impl( mp_size_t<I>() ): throw bad_variant_access();
-
-#endif
+    return ( v.index() == I? (void)0: throw bad_variant_access() ), v._get_impl( mp_size_t<I>() );
 }
 
 template<std::size_t I, class... T> constexpr variant_alternative_t<I, variant<T...>>&& get(variant<T...>&& v)
 {
     static_assert( I < sizeof...(T), "Index out of bounds" );
-
-#if BOOST_WORKAROUND( BOOST_MSVC, <= 1910 )
-
-    return std::move( v.index() == I? v._get_impl( mp_size_t<I>() ): ( throw bad_variant_access(), v._get_impl( mp_size_t<I>() ) ) );
-
-#else
-
-    return v.index() == I? std::move( v._get_impl( mp_size_t<I>() ) ): throw bad_variant_access();
-
-#endif
+    return ( v.index() == I? (void)0: throw bad_variant_access() ), std::move( v._get_impl( mp_size_t<I>() ) );
 }
 
 template<std::size_t I, class... T> constexpr variant_alternative_t<I, variant<T...> const>& get(variant<T...> const& v)
 {
     static_assert( I < sizeof...(T), "Index out of bounds" );
-
-#if BOOST_WORKAROUND( BOOST_MSVC, <= 1910 )
-
-    return v.index() == I? v._get_impl( mp_size_t<I>() ): ( throw bad_variant_access(), v._get_impl( mp_size_t<I>() ) );
-
-#else
-
-    return v.index() == I? v._get_impl( mp_size_t<I>() ): throw bad_variant_access();
-
-#endif
+    return ( v.index() == I? (void)0: throw bad_variant_access() ), v._get_impl( mp_size_t<I>() );
 }
 
 template<std::size_t I, class... T> constexpr variant_alternative_t<I, variant<T...> const>&& get(variant<T...> const&& v)
 {
     static_assert( I < sizeof...(T), "Index out of bounds" );
-
-#if BOOST_WORKAROUND( BOOST_MSVC, <= 1910 )
-
-    return std::move( v.index() == I? v._get_impl( mp_size_t<I>() ): ( throw bad_variant_access(), v._get_impl( mp_size_t<I>() ) ) );
-
-#else
-
-    return v.index() == I? std::move( v._get_impl( mp_size_t<I>() ) ): throw bad_variant_access();
-
-#endif
+    return ( v.index() == I? (void)0: throw bad_variant_access() ), std::move( v._get_impl( mp_size_t<I>() ) );
 }
 
 // get
diff --git a/test/Jamfile b/test/Jamfile
index 766c254..3a35203 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -15,3 +15,4 @@ run variant_size.cpp : : : $(REQ) ;
 run variant_alternative.cpp : : : $(REQ) ;
 run holds_alternative.cpp : : : $(REQ) ;
 run holds_alternative_cx.cpp : : : $(REQ) ;
+run get_by_index.cpp : : : $(REQ) ;
diff --git a/test/get_by_index.cpp b/test/get_by_index.cpp
new file mode 100644
index 0000000..7491d9b
--- /dev/null
+++ b/test/get_by_index.cpp
@@ -0,0 +1,184 @@
+
+// Copyright 2017 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/variant2/variant.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+#include <type_traits>
+#include <utility>
+#include <string>
+
+using namespace boost::variant2;
+
+int main()
+{
+    {
+        variant<int> v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int*>));
+    }
+
+    {
+        variant<int> const v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int const&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int const&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int const*>));
+    }
+
+    {
+        variant<int const> v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int const&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int const&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int const*>));
+    }
+
+    {
+        variant<int volatile> const v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int const volatile&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int const volatile&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int const volatile*>));
+    }
+
+    {
+        variant<int> v;
+
+        BOOST_TEST_EQ( get<0>(v), 0 );
+        BOOST_TEST_EQ( get_if<0>(&v), &get<0>(v) );
+    }
+
+    {
+        variant<int> v( 1 );
+
+        BOOST_TEST_EQ( get<0>(v), 1 );
+        BOOST_TEST_EQ( get_if<0>(&v), &get<0>(v) );
+    }
+
+    {
+        variant<int, float> v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int*>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(v)), float&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(std::move(v))), float&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<1>(&v)), float*>));
+    }
+
+    {
+        variant<int, float> const v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int const&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int const&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int const*>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(v)), float const&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(std::move(v))), float const&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<1>(&v)), float const*>));
+    }
+
+    {
+        variant<int const, float volatile> v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int const&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int const&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int const*>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(v)), float volatile&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(std::move(v))), float volatile&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<1>(&v)), float volatile*>));
+    }
+
+    {
+        variant<int const, float volatile> const v;
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(v)), int const&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<0>(std::move(v))), int const&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<0>(&v)), int const*>));
+
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(v)), float const volatile&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get<1>(std::move(v))), float const volatile&&>));
+        BOOST_TEST_TRAIT_TRUE((std::is_same<decltype(get_if<1>(&v)), float const volatile*>));
+    }
+
+    {
+        variant<int, float> v;
+
+        BOOST_TEST_EQ( get<0>(v), 0 );
+        BOOST_TEST_EQ( get_if<0>(&v), &get<0>(v) );
+
+        BOOST_TEST_THROWS( get<1>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<1>(&v), nullptr );
+    }
+
+    {
+        variant<int, float> v( 1 );
+
+        BOOST_TEST_EQ( get<0>(v), 1 );
+        BOOST_TEST_EQ( get_if<0>(&v), &get<0>(v) );
+
+        BOOST_TEST_THROWS( get<1>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<1>(&v), nullptr );
+    }
+
+    {
+        variant<int, float> v( 3.14f );
+
+        BOOST_TEST_THROWS( get<0>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<0>(&v), nullptr );
+
+        BOOST_TEST_EQ( get<1>(v), 3.14f );
+        BOOST_TEST_EQ( get_if<1>(&v), &get<1>(v) );
+    }
+
+    {
+        variant<int, float, float> v;
+
+        BOOST_TEST_EQ( get<0>(v), 0 );
+        BOOST_TEST_EQ( get_if<0>(&v), &get<0>(v) );
+
+        BOOST_TEST_THROWS( get<1>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<1>(&v), nullptr );
+
+        BOOST_TEST_THROWS( get<2>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<2>(&v), nullptr );
+    }
+
+    {
+        variant<int, float, float> v( 1 );
+
+        BOOST_TEST_EQ( get<0>(v), 1 );
+        BOOST_TEST_EQ( get_if<0>(&v), &get<0>(v) );
+
+        BOOST_TEST_THROWS( get<1>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<1>(&v), nullptr );
+
+        BOOST_TEST_THROWS( get<2>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<2>(&v), nullptr );
+    }
+
+    {
+        variant<int, int, float> v( 3.14f );
+
+        BOOST_TEST_THROWS( get<0>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<0>(&v), nullptr );
+
+        BOOST_TEST_THROWS( get<1>(v), bad_variant_access );
+        BOOST_TEST_EQ( get_if<1>(&v), nullptr );
+
+        BOOST_TEST_EQ( get<2>(v), 3.14f );
+        BOOST_TEST_EQ( get_if<2>(&v), &get<2>(v) );
+    }
+
+    return boost::report_errors();
+}