Ticket #7911: varant_noexcept.patch

boost/variant/variant.hpp

@@ -226 +226 @@
 
 #endif // BOOST_MPL_CFG_MSVC_60_ETI_BUG workaround
 
+#ifndef BOOST_NO_CXX11_NOEXCEPT
 ///////////////////////////////////////////////////////////////////////////////
+// (detail) metafunction is_variant_move_noexcept
+//
+// Returns true_type if all the types are nothrow move constructible.
+//
+template <class Types>
+struct is_variant_move_noexcept {
+    typedef typename boost::mpl::find_if<
+        Types, mpl::not_<boost::is_nothrow_move_constructible<boost::mpl::_1> >
+    >::type iterator_t;
+
+    typedef typename boost::mpl::end<Types>::type end_t;
+    typedef typename boost::is_same<
+        iterator_t, end_t
+    >::type type;
+};
+#endif // BOOST_NO_CXX11_NOEXCEPT
+
+///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction make_storage
 //
 // Provides an aligned storage type capable of holding any of the types
@@ -1289 +1308 @@
           internal_types, never_uses_backup_flag
         >::type storage_t;
 
+#ifndef BOOST_NO_CXX11_NOEXCEPT
+    typedef typename detail::variant::is_variant_move_noexcept<
+        internal_types
+    > variant_move_noexcept;
+#endif
+
 private: // helpers, for representation (below)
 
     // which_ on:
@@ -1375 +1400 @@
 
 public: // structors
 
-    ~variant()
+    ~variant() BOOST_NOEXCEPT
     {
         destroy_content();
     }
@@ -1766 +1791 @@
     }
     
 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-    variant(variant&& operand)
+    variant(variant&& operand) BOOST_NOEXCEPT_IF(variant_move_noexcept::type::value)
     {
         // Move the value of operand into *this...
         detail::variant::move_into visitor( storage_.address() );
@@ -2177 +2202 @@
     }
 
 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-    variant& operator=(variant&& rhs)
+    variant& operator=(variant&& rhs) BOOST_NOEXCEPT_IF(variant_move_noexcept::type::value)
     {
         variant_assign( detail::variant::move(rhs) );
         return *this;

libs/variant/test/rvalue_test.cpp

@@ -3 +3 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2012
-// Antony Polukhin
+// Copyright (c) 2012-2013 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -14 +13 @@
 
 #include "boost/test/minimal.hpp"
 #include "boost/variant.hpp"
+#include "boost/type_traits/is_nothrow_move_assignable.hpp"
 
 // This test requires rvalue references support
 
@@ -34 +34 @@
     BOOST_CHECK(true);
 }
 
+void run_moves_are_noexcept()
+{
+    BOOST_CHECK(true);
+}
+
 #else 
 
 class move_copy_conting_class {
@@ -177 +182 @@
     BOOST_CHECK(vi.which() == 1);
 }
 
+void run_moves_are_noexcept() {
+#ifndef BOOST_NO_CXX11_NOEXCEPT
+    typedef boost::variant<int, short, double> variant_noexcept_t;
+    BOOST_CHECK(boost::is_nothrow_move_assignable<variant_noexcept_t>::value);
+    BOOST_CHECK(boost::is_nothrow_move_constructible<variant_noexcept_t>::value);
+
+    typedef boost::variant<int, short, double, move_only_structure> variant_except_t;
+    BOOST_CHECK(!boost::is_nothrow_move_assignable<variant_except_t>::value);
+    BOOST_CHECK(!boost::is_nothrow_move_constructible<variant_except_t>::value);
 #endif
+}
 
+#endif
 
+
 int test_main(int , char* [])
 {
    run();
    run1();
    run_move_only();
+   run_moves_are_noexcept();
    return 0;
-}
- No newline at end of file
+}