// file      : butl/config -*- C++ -*-
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#ifndef BUTL_CONFIG
#define BUTL_CONFIG

#include <cstddef> // _LIBCPP_VERSION, __GLIBCXX__

// thread_local
//
// If this macro is undefined then we assume one can use __thread but only
// for values that do not require dynamic (runtime) initialization.
//
// Apparently Apple's Clang "temporarily disabled" C++11 thread_local
// until they can implement a "fast" version, which reportedly happened in
// XCode 8. So for now we will continue using __thread for this target.
//
#ifdef __apple_build_version__
#  if __apple_build_version__ >= 8000000
#    define BUTL_CXX11_THREAD_LOCAL
#  endif
#else
#    define BUTL_CXX11_THREAD_LOCAL
#endif

// std::uncaught_exceptions()
//
// VC has it since 1900 which is the lowest version we support.
//
#if defined(_MSC_VER)
#  define BUTL_CXX17_UNCAUGHT_EXCEPTIONS
//
// Clang's libc++ seems to have it for a while (but not before 1200) so we
// assume it's there from 1200 (it doesn't define a feature test macros). But
// not for MacOS, where it is explicitly marked as unavailable until MacOS
// 10.12.
//
#elif defined(_LIBCPP_VERSION) && _LIBCPP_VERSION >= 1200
#  if !defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) || \
               __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101200
#    define BUTL_CXX17_UNCAUGHT_EXCEPTIONS
#  endif
//
// GCC libstdc++ has it since GCC 6 and it defines the feature test macro.
// We will also use this for any other runtime.
//
#elif defined(__cpp_lib_uncaught_exceptions)
#  define BUTL_CXX17_UNCAUGHT_EXCEPTIONS
#endif

#endif // BUTL_CONFIG