1 //-----------------------------------------------------------------------------
2 // boost variant/detail/forced_return.hpp header file
3 // See http://www.boost.org for updates, documentation, and revision history.
4 //-----------------------------------------------------------------------------
5 //
6 // Copyright (c) 2003 Eric Friedman
7 // Copyright (c) 2015-2021 Antony Polukhin
8 //
9 // Distributed under the Boost Software License, Version 1.0. (See
10 // accompanying file LICENSE_1_0.txt or copy at
11 // http://www.boost.org/LICENSE_1_0.txt)
12 
13 #ifndef BOOST_VARIANT_DETAIL_FORCED_RETURN_HPP
14 #define BOOST_VARIANT_DETAIL_FORCED_RETURN_HPP
15 
16 #include <boost/config.hpp>
17 #include <boost/assert.hpp>
18 
19 
20 #ifdef BOOST_MSVC
21 # pragma warning( push )
22 # pragma warning( disable : 4702 ) // unreachable code
23 #endif
24 
25 namespace boost { namespace detail { namespace variant {
26 
27 ///////////////////////////////////////////////////////////////////////////////
28 // (detail) function template forced_return
29 //
30 // Logical error to permit invocation at runtime, but (artificially) satisfies
31 // compile-time requirement of returning a result value.
32 //
33 template <typename T>
34 BOOST_NORETURN inline T
forced_return()35 forced_return()
36 {
37     // logical error: should never be here! (see above)
38     BOOST_ASSERT(false);
39 
40     T (*dummy)() = 0;
41     (void)dummy;
42     BOOST_UNREACHABLE_RETURN(dummy());
43 }
44 
45 }}} // namespace boost::detail::variant
46 
47 
48 #ifdef BOOST_MSVC
49 # pragma warning( pop )
50 #endif
51 
52 #endif // BOOST_VARIANT_DETAIL_FORCED_RETURN_HPP
53