From dcbe62c6bf59cf98adc1d42a27c19689c1f488f9 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Wed, 6 Feb 2019 02:02:40 +0200
Subject: [PATCH] Add BOOST_TEST_TRAIT_SAME

---
 include/boost/core/lightweight_test_trait.hpp | 29 ++++++++++++++-
 test/Jamfile.v2                               |  2 +
 test/lightweight_test_test4.cpp               | 36 ++++++++++++++++++
 test/lightweight_test_test5.cpp               | 37 +++++++++++++++++++
 4 files changed, 103 insertions(+), 1 deletion(-)
 create mode 100644 test/lightweight_test_test4.cpp
 create mode 100644 test/lightweight_test_test5.cpp

diff --git a/include/boost/core/lightweight_test_trait.hpp b/include/boost/core/lightweight_test_trait.hpp
index 13aa3f0..0e7e1ab 100644
--- a/include/boost/core/lightweight_test_trait.hpp
+++ b/include/boost/core/lightweight_test_trait.hpp
@@ -9,7 +9,7 @@
 
 // boost/core/lightweight_test_trait.hpp
 //
-// BOOST_TEST_TRAIT_TRUE, BOOST_TEST_TRAIT_FALSE
+// BOOST_TEST_TRAIT_TRUE, BOOST_TEST_TRAIT_FALSE, BOOST_TEST_TRAIT_SAME
 //
 // Copyright 2014 Peter Dimov
 //
@@ -19,6 +19,7 @@
 
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/typeinfo.hpp>
+#include <boost/core/is_same.hpp>
 
 namespace boost
 {
@@ -46,11 +47,37 @@ template< class T > inline void test_trait_impl( char const * trait, void (*)( T
     }
 }
 
+template<class T1, class T2> inline bool test_trait_same_impl_( boost::core::is_same<T1, T2> )
+{
+    return boost::core::is_same<T1, T2>::value;
+}
+
+template<class T1, class T2> inline void test_trait_same_impl( char const * types, void (*)( boost::core::is_same<T1, T2> ),
+  char const * file, int line, char const * function )
+{
+    if( test_trait_same_impl_( boost::core::is_same<T1, T2>() ) )
+    {
+        test_results();
+    }
+    else
+    {
+        BOOST_LIGHTWEIGHT_TEST_OSTREAM
+            << file << "(" << line << "): test 'is_same<" << types << ">'"
+            << " failed in function '" << function
+            << "' ('" << boost::core::demangled_name( BOOST_CORE_TYPEID(T1) )
+            << "' != '" << boost::core::demangled_name( BOOST_CORE_TYPEID(T2) ) << "')"
+            << std::endl;
+
+        ++test_results().errors();
+    }
+}
+
 } // namespace detail
 
 } // namespace boost
 
 #define BOOST_TEST_TRAIT_TRUE(type) ( ::boost::detail::test_trait_impl(#type, (void(*)type)0, true, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION) )
 #define BOOST_TEST_TRAIT_FALSE(type) ( ::boost::detail::test_trait_impl(#type, (void(*)type)0, false, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION) )
+#define BOOST_TEST_TRAIT_SAME(...) ( ::boost::detail::test_trait_same_impl(#__VA_ARGS__, (void(*)(::boost::core::is_same<__VA_ARGS__>))0, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION) )
 
 #endif // #ifndef BOOST_CORE_LIGHTWEIGHT_TEST_TRAIT_HPP
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 7b7875d..ea53b58 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -76,6 +76,8 @@ run lightweight_test_lt_le_test.cpp ;
 run lightweight_test_gt_ge_test.cpp ;
 run lightweight_test_eq_nullptr.cpp ;
 run lightweight_test_test3.cpp ;
+run lightweight_test_test4.cpp ;
+run lightweight_test_test5.cpp ;
 
 run-fail lightweight_test_fail.cpp ;
 run-fail lightweight_test_fail2.cpp ;
diff --git a/test/lightweight_test_test4.cpp b/test/lightweight_test_test4.cpp
new file mode 100644
index 0000000..a3e8b04
--- /dev/null
+++ b/test/lightweight_test_test4.cpp
@@ -0,0 +1,36 @@
+//
+// Test for BOOST_TEST_TRAIT_SAME
+//
+// Copyright 2014, 2019 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/core/lightweight_test_trait.hpp>
+
+struct X
+{
+    typedef int type;
+};
+
+template<class T1, class T2> struct Y
+{
+    typedef T1 type;
+};
+
+int main()
+{
+    BOOST_TEST_TRAIT_SAME(X, X);
+    BOOST_TEST_TRAIT_SAME(void, void);
+    BOOST_TEST_TRAIT_SAME(char[1], char[1]);
+    BOOST_TEST_TRAIT_SAME(char[], char[]);
+    BOOST_TEST_TRAIT_SAME(void(), void());
+    BOOST_TEST_TRAIT_SAME(X::type, X::type);
+    BOOST_TEST_TRAIT_SAME(X::type, Y<int, float>::type);
+    BOOST_TEST_TRAIT_SAME(Y<int, float>, Y<int, float>);
+    BOOST_TEST_TRAIT_SAME(Y<void, float>::type, void);
+
+    return boost::report_errors();
+}
diff --git a/test/lightweight_test_test5.cpp b/test/lightweight_test_test5.cpp
new file mode 100644
index 0000000..122dced
--- /dev/null
+++ b/test/lightweight_test_test5.cpp
@@ -0,0 +1,37 @@
+//
+// Negative test for BOOST_TEST_TRAIT_SAME
+//
+// Copyright 2014, 2019 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/core/lightweight_test_trait.hpp>
+
+struct X
+{
+    typedef int type;
+};
+
+template<class T1, class T2> struct Y
+{
+    typedef T1 type;
+};
+
+int main()
+{
+    BOOST_TEST_TRAIT_SAME(char[1], char[2]);
+    BOOST_TEST_TRAIT_SAME(char[1], char[]);
+    BOOST_TEST_TRAIT_SAME(char[1], char*);
+    BOOST_TEST_TRAIT_SAME(void(), void(int));
+    BOOST_TEST_TRAIT_SAME(void(), void(*)());
+    BOOST_TEST_TRAIT_SAME(X, void);
+    BOOST_TEST_TRAIT_SAME(X::type, void);
+    BOOST_TEST_TRAIT_SAME(X, Y<void, void>);
+    BOOST_TEST_TRAIT_SAME(X::type, Y<float, int>::type);
+    BOOST_TEST_TRAIT_SAME(Y<int, float>, Y<int, double>);
+
+    return boost::report_errors() == 10;
+}