Line data    Source code

       1             : #ifndef BOOST_CORE_LAUNDER_HPP_INCLUDED
       2             : #define BOOST_CORE_LAUNDER_HPP_INCLUDED
       3             : 
       4             : // MS compatible compilers support #pragma once
       5             : 
       6             : #if defined(_MSC_VER) && (_MSC_VER >= 1020)
       7             : # pragma once
       8             : #endif
       9             : 
      10             : //  Copyright 2023 Peter Dimov
      11             : //  Distributed under the Boost Software License, Version 1.0.
      12             : //  https://www.boost.org/LICENSE_1_0.txt
      13             : 
      14             : #include <boost/config.hpp>
      15             : 
      16             : #if defined(__has_builtin)
      17             : # if __has_builtin(__builtin_launder)
      18             : #  define BOOST_CORE_HAS_BUILTIN_LAUNDER
      19             : # endif
      20             : #endif
      21             : 
      22             : #if defined(BOOST_MSVC) && BOOST_MSVC < 1920
      23             : 
      24             : // msvc-14.1 suffers from internal compiler errors when using std::launder
      25             : // https://github.com/boostorg/core/issues/160
      26             : // https://github.com/boostorg/optional/issues/122
      27             : 
      28             : #elif (BOOST_CXX_VERSION >= 201703L) && !defined(BOOST_CORE_HAS_BUILTIN_LAUNDER)
      29             : 
      30             : #include <new>
      31             : 
      32             : #if defined(__cpp_lib_launder)
      33             : # define BOOST_CORE_HAS_STD_LAUNDER
      34             : #endif
      35             : 
      36             : #endif
      37             : 
      38             : namespace boost
      39             : {
      40             : namespace core
      41             : {
      42             : 
      43             : #if defined(BOOST_CORE_HAS_BUILTIN_LAUNDER)
      44             : 
      45      750363 : template<class T> T* launder( T* p )
      46             : {
      47      750363 :     return __builtin_launder( p );
      48             : }
      49             : 
      50             : #elif defined(BOOST_CORE_HAS_STD_LAUNDER)
      51             : 
      52             : template<class T> T* launder( T* p )
      53             : {
      54             :     return std::launder( p );
      55             : }
      56             : 
      57             : #else
      58             : 
      59             : template<class T> T* launder( T* p )
      60             : {
      61             :     return p;
      62             : }
      63             : 
      64             : #endif
      65             : 
      66             : } // namespace core
      67             : } // namespace boost
      68             : 
      69             : #endif  // #ifndef BOOST_CORE_LAUNDER_HPP_INCLUDED