aboutsummaryrefslogtreecommitdiff
path: root/butl/ft/shared_mutex
blob: 73bd3e94703ea548264c0ab847ec16156f772207 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
// file      : butl/ft/shared_mutex -*- C++ -*-
// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#ifndef BUTL_FT_SHARED_MUTEX
#define BUTL_FT_SHARED_MUTEX

#include <cstddef>      // _LIBCPP_VERSION
#include <shared_mutex>

// __cpp_lib_shared_mutex
//
#ifndef __cpp_lib_shared_mutex
   //
   // VC has it since 1900.
   //
#  if defined(_MSC_VER)
#    if _MSC_VER >= 1900
#      define __cpp_lib_shared_mutex 201505
#    endif
   //
   // Clang's libc++ seems to have it for a while (but not before 1200) so we
   // assume it's there from 1200. It's also only enabled after C++14. But not
   // for MacOS, where it is explicitly marked as unavailable until MacOS
   // 10.12.
   //
#  elif defined(_LIBCPP_VERSION) && defined(_LIBCPP_STD_VER)
#    if _LIBCPP_VERSION >= 1200 &&                              \
  _LIBCPP_STD_VER > 14 &&                                       \
  (!defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) ||   \
   __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101200)
#      define __cpp_lib_shared_mutex 201505
#    endif
   //
   // GCC libstdc++ has it since GCC 6 and it defines the feature test macro.
   // We will also use this for any other runtime.
   //
#  endif
#endif

// __cpp_lib_shared_mutex
//
#ifndef __cpp_lib_shared_timed_mutex
#  define __cpp_lib_shared_timed_mutex 201402
#endif

#endif // BUTL_FT_SHARED_MUTEX