Make boost::tuple tuple-like to support structured bindings

2018-01-03 19:26:11 +02:00
parent c51d8a9495
commit 16731d2689
6 changed files with 247 additions and 10 deletions
@@ -0,0 +1,77 @@
+// Copyright 2017 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/tuple/tuple.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if defined(BOOST_NO_CXX17_STRUCTURED_BINDINGS)
+
+BOOST_PRAGMA_MESSAGE("Skipping structured bindings test, not supported")
+int main() {}
+
+#else
+
+int main()
+{
+    // make_tuple
+
+    {
+        auto [x1] = boost::make_tuple( 1 );
+        BOOST_TEST_EQ( x1, 1 );
+    }
+
+    {
+        auto [x1, x2] = boost::make_tuple( 1, 2 );
+        BOOST_TEST_EQ( x1, 1 );
+        BOOST_TEST_EQ( x2, 2 );
+    }
+
+    {
+        auto [x1, x2, x3] = boost::make_tuple( 1, 2, 3 );
+        BOOST_TEST_EQ( x1, 1 );
+        BOOST_TEST_EQ( x2, 2 );
+        BOOST_TEST_EQ( x3, 3 );
+    }
+
+    {
+        auto [x1, x2, x3, x4] = boost::make_tuple( 1, 2, 3, 4 );
+        BOOST_TEST_EQ( x1, 1 );
+        BOOST_TEST_EQ( x2, 2 );
+        BOOST_TEST_EQ( x3, 3 );
+        BOOST_TEST_EQ( x4, 4 );
+    }
+
+    // tuple
+
+    {
+        auto [x1] = boost::tuple<int>( 1 );
+        BOOST_TEST_EQ( x1, 1 );
+    }
+
+    {
+        auto [x1, x2] = boost::tuple<int, int>( 1, 2 );
+        BOOST_TEST_EQ( x1, 1 );
+        BOOST_TEST_EQ( x2, 2 );
+    }
+
+    {
+        auto [x1, x2, x3] = boost::tuple<int, int, int>( 1, 2, 3 );
+        BOOST_TEST_EQ( x1, 1 );
+        BOOST_TEST_EQ( x2, 2 );
+        BOOST_TEST_EQ( x3, 3 );
+    }
+
+    {
+        auto [x1, x2, x3, x4] = boost::tuple<int, int, int, int>( 1, 2, 3, 4 );
+        BOOST_TEST_EQ( x1, 1 );
+        BOOST_TEST_EQ( x2, 2 );
+        BOOST_TEST_EQ( x3, 3 );
+        BOOST_TEST_EQ( x4, 4 );
+    }
+
+    return boost::report_errors();
+}
+
+#endif