text: //  (C) Copyright John Maddock 2001 - 2003.
  //  (C) Copyright Darin Adler 2001 - 2002.
  //  (C) Copyright Peter Dimov 2001.
  //  (C) Copyright Aleksey Gurtovoy 2002.
  //  (C) Copyright David Abrahams 2002 - 2003.
  //  (C) Copyright Beman Dawes 2002 - 2003.
  //  Use, modification and distribution are subject to the
  //  Boost Software License, Version 1.0. (See accompanying file
  //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  
  //  See http://www.boost.org for most recent version.
  //
  //  Microsoft Visual C++ compiler setup:
  //
  //  We need to be careful with the checks in this file, as contrary
  //  to popular belief there are versions with _MSC_VER with the final
  //  digit non-zero (mainly the MIPS cross compiler).
  //
  //  So we either test _MSC_VER >= XXXX or else _MSC_VER < XXXX.
  //  No other comparisons (==, >, or <=) are safe.
  //
  
  #define BOOST_MSVC _MSC_VER
  
  //
  // Helper macro BOOST_MSVC_FULL_VER for use in Boost code:
  //
  #if _MSC_FULL_VER > 100000000
  #  define BOOST_MSVC_FULL_VER _MSC_FULL_VER
  #else
  #  define BOOST_MSVC_FULL_VER (_MSC_FULL_VER * 10)
  #endif
  
  // Attempt to suppress VC6 warnings about the length of decorated names (obsolete):
  #pragma warning( disable : 4503 ) // warning: decorated name length exceeded
  
  #define BOOST_HAS_PRAGMA_ONCE
  
  //
  // versions check:
  // we don't support Visual C++ prior to version 7.1:
  #if _MSC_VER < 1310
  #  error "Compiler not supported or configured - please reconfigure"
  #endif
  
  #if _MSC_FULL_VER < 180020827
  #  define BOOST_NO_FENV_H
  #endif
  
  #if _MSC_VER < 1400
  // although a conforming signature for swprint exists in VC7.1
  // it appears not to actually work:
  #  define BOOST_NO_SWPRINTF
  // Our extern template tests also fail for this compiler:
  #  define BOOST_NO_CXX11_EXTERN_TEMPLATE
  // Variadic macros do not exist for VC7.1 and lower
  #  define BOOST_NO_CXX11_VARIADIC_MACROS
  #  define BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS
  #endif
  
  #if _MSC_VER < 1500  // 140X == VC++ 8.0
  #  define BOOST_NO_MEMBER_TEMPLATE_FRIENDS
  #endif
  
  #if _MSC_VER < 1600  // 150X == VC++ 9.0
     // A bug in VC9:
  #  define BOOST_NO_ADL_BARRIER
  #endif
  
  
  #ifndef _NATIVE_WCHAR_T_DEFINED
  #  define BOOST_NO_INTRINSIC_WCHAR_T
  #endif
  
  //
  // check for exception handling support:
  #if !defined(_CPPUNWIND) && !defined(BOOST_NO_EXCEPTIONS)
  #  define BOOST_NO_EXCEPTIONS
  #endif
  
  //
  // __int64 support:
  //
  #define BOOST_HAS_MS_INT64
  #if defined(_MSC_EXTENSIONS) || (_MSC_VER >= 1400)
  #   define BOOST_HAS_LONG_LONG
  #else
  #   define BOOST_NO_LONG_LONG
  #endif
  #if (_MSC_VER >= 1400) && !defined(_DEBUG)
  #   define BOOST_HAS_NRVO
  #endif
  #if _MSC_VER >= 1600  // 160X == VC++ 10.0
  #  define BOOST_HAS_PRAGMA_DETECT_MISMATCH
  #endif
  //
  // disable Win32 API's if compiler extensions are
  // turned off:
  //
  #if !defined(_MSC_EXTENSIONS) && !defined(BOOST_DISABLE_WIN32)
  #  define BOOST_DISABLE_WIN32
  #endif
  #if !defined(_CPPRTTI) && !defined(BOOST_NO_RTTI)
  #  define BOOST_NO_RTTI
  #endif
  
  //
  // TR1 features:
  //
  #if (_MSC_VER >= 1700) && defined(_HAS_CXX17) && (_HAS_CXX17 > 0)
  // # define BOOST_HAS_TR1_HASH			// don't know if this is true yet.
  // # define BOOST_HAS_TR1_TYPE_TRAITS	// don't know if this is true yet.
  # define BOOST_HAS_TR1_UNORDERED_MAP
  # define BOOST_HAS_TR1_UNORDERED_SET
  #endif
  
  //
  // C++0x features
  //
  //   See above for BOOST_NO_LONG_LONG
  
  // C++ features supported by VC++ 10 (aka 2010)
  //
  #if _MSC_VER < 1600
  #  define BOOST_NO_CXX11_AUTO_DECLARATIONS
  #  define BOOST_NO_CXX11_AUTO_MULTIDECLARATIONS
  #  define BOOST_NO_CXX11_LAMBDAS
  #  define BOOST_NO_CXX11_RVALUE_REFERENCES
  #  define BOOST_NO_CXX11_STATIC_ASSERT
  #  define BOOST_NO_CXX11_NULLPTR
  #  define BOOST_NO_CXX11_DECLTYPE
  #endif // _MSC_VER < 1600
  
  #if _MSC_VER >= 1600
  #  define BOOST_HAS_STDINT_H
  #endif
  
  // C++11 features supported by VC++ 11 (aka 2012)
  //
  #if _MSC_VER < 1700
  #  define BOOST_NO_CXX11_FINAL
  #  define BOOST_NO_CXX11_RANGE_BASED_FOR
  #  define BOOST_NO_CXX11_SCOPED_ENUMS
  #endif // _MSC_VER < 1700
  
  // C++11 features supported by VC++ 12 (aka 2013).
  //
  #if _MSC_FULL_VER < 180020827
  #  define BOOST_NO_CXX11_DEFAULTED_FUNCTIONS
  #  define BOOST_NO_CXX11_DELETED_FUNCTIONS
  #  define BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS
  #  define BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS
  #  define BOOST_NO_CXX11_RAW_LITERALS
  #  define BOOST_NO_CXX11_TEMPLATE_ALIASES
  #  define BOOST_NO_CXX11_TRAILING_RESULT_TYPES
  #  define BOOST_NO_CXX11_VARIADIC_TEMPLATES
  #  define BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX
  #  define BOOST_NO_CXX11_DECLTYPE_N3276
  #endif
  
  #if _MSC_FULL_VER >= 180020827
  #define BOOST_HAS_EXPM1
  #define BOOST_HAS_LOG1P
  #endif
  
  // C++11 features supported by VC++ 14 (aka 2015)
  //
  #if (_MSC_FULL_VER < 190023026)
  #  define BOOST_NO_CXX11_NOEXCEPT
  #  define BOOST_NO_CXX11_REF_QUALIFIERS
  #  define BOOST_NO_CXX11_USER_DEFINED_LITERALS
  #  define BOOST_NO_CXX11_ALIGNAS
  #  define BOOST_NO_CXX11_INLINE_NAMESPACES
  #  define BOOST_NO_CXX11_CHAR16_T
  #  define BOOST_NO_CXX11_CHAR32_T
  #  define BOOST_NO_CXX11_UNICODE_LITERALS
  #  define BOOST_NO_CXX14_DECLTYPE_AUTO
  #  define BOOST_NO_CXX14_INITIALIZED_LAMBDA_CAPTURES
  #  define BOOST_NO_CXX14_RETURN_TYPE_DEDUCTION
  #  define BOOST_NO_CXX14_BINARY_LITERALS
  #  define BOOST_NO_CXX14_GENERIC_LAMBDAS
  #  define BOOST_NO_CXX14_DIGIT_SEPARATORS
  #  define BOOST_NO_CXX11_THREAD_LOCAL
  #endif
  // C++11 features supported by VC++ 14 update 3 (aka 2015)
  //
  #if (_MSC_FULL_VER < 190024210)
  #  define BOOST_NO_CXX14_VARIABLE_TEMPLATES
  #  define BOOST_NO_SFINAE_EXPR
  #  define BOOST_NO_CXX11_CONSTEXPR
  #endif
  
  // C++14 features supported by VC++ 14.1 (Visual Studio 2017)
  //
  #if (_MSC_VER < 1910)
  #  define BOOST_NO_CXX14_AGGREGATE_NSDMI
  #endif
  
  // C++17 features supported by VC++ 14.1 (Visual Studio 2017) Update 3
  //
  #if (_MSC_VER < 1911) || (_MSVC_LANG < 201703)
  #  define BOOST_NO_CXX17_STRUCTURED_BINDINGS
  #endif
  
  // MSVC including version 14 has not yet completely
  // implemented value-initialization, as is reported:
  // "VC++ does not value-initialize members of derived classes without
  // user-declared constructor", reported in 2009 by Sylvester Hesp:
  // https://connect.microsoft.com/VisualStudio/feedback/details/484295
  // "Presence of copy constructor breaks member class initialization",
  // reported in 2009 by Alex Vakulenko:
  // https://connect.microsoft.com/VisualStudio/feedback/details/499606
  // "Value-initialization in new-expression", reported in 2005 by
  // Pavel Kuznetsov (MetaCommunications Engineering):
  // https://connect.microsoft.com/VisualStudio/feedback/details/100744
  // Reported again by John Maddock in 2015 for VC14:
  // https://connect.microsoft.com/VisualStudio/feedback/details/1582233/c-subobjects-still-not-value-initialized-correctly
  // See also: http://www.boost.org/libs/utility/value_init.htm#compiler_issues
  // (Niels Dekker, LKEB, May 2010)
  #define BOOST_NO_COMPLETE_VALUE_INITIALIZATION
  //
  // C++ 11:
  //
  #define BOOST_NO_TWO_PHASE_NAME_LOOKUP
  #define BOOST_NO_CXX11_SFINAE_EXPR
  // C++ 14:
  #  define BOOST_NO_CXX14_CONSTEXPR
  // C++ 17:
  #define BOOST_NO_CXX17_INLINE_VARIABLES
  #define BOOST_NO_CXX17_FOLD_EXPRESSIONS
  
  //
  // Things that don't work in clr mode:
  //
  #ifdef _M_CEE
  #ifndef BOOST_NO_CXX11_THREAD_LOCAL
  #  define BOOST_NO_CXX11_THREAD_LOCAL
  #endif
  #ifndef BOOST_NO_SFINAE_EXPR
  #  define BOOST_NO_SFINAE_EXPR
  #endif
  #ifndef BOOST_NO_CXX11_REF_QUALIFIERS
  #  define BOOST_NO_CXX11_REF_QUALIFIERS
  #endif
  #endif
  #ifdef _M_CEE_PURE
  #ifndef BOOST_NO_CXX11_CONSTEXPR
  #  define BOOST_NO_CXX11_CONSTEXPR
  #endif
  #endif
  
  //
  // prefix and suffix headers:
  //
  #ifndef BOOST_ABI_PREFIX
  #  define BOOST_ABI_PREFIX "boost/config/abi/msvc_prefix.hpp"
  #endif
  #ifndef BOOST_ABI_SUFFIX
  #  define BOOST_ABI_SUFFIX "boost/config/abi/msvc_suffix.hpp"
  #endif
  
  #ifndef BOOST_COMPILER
  // TODO:
  // these things are mostly bogus. 1200 means version 12.0 of the compiler. The
  // artificial versions assigned to them only refer to the versions of some IDE
  // these compilers have been shipped with, and even that is not all of it. Some
  // were shipped with freely downloadable SDKs, others as crosscompilers in eVC.
  // IOW, you can't use these 'versions' in any sensible way. Sorry.
  # if defined(UNDER_CE)
  #   if _MSC_VER < 1400
        // Note: I'm not aware of any CE compiler with version 13xx
  #      if defined(BOOST_ASSERT_CONFIG)
  #         error "Unknown EVC++ compiler version - please run the configure tests and report the results"
  #      else
  #         pragma message("Unknown EVC++ compiler version - please run the configure tests and report the results")
  #      endif
  #   elif _MSC_VER < 1500
  #     define BOOST_COMPILER_VERSION evc8
  #   elif _MSC_VER < 1600
  #     define BOOST_COMPILER_VERSION evc9
  #   elif _MSC_VER < 1700
  #     define BOOST_COMPILER_VERSION evc10
  #   elif _MSC_VER < 1800 
  #     define BOOST_COMPILER_VERSION evc11 
  #   elif _MSC_VER < 1900 
  #     define BOOST_COMPILER_VERSION evc12
  #   elif _MSC_VER < 2000  
  #     define BOOST_COMPILER_VERSION evc14
  #   else
  #      if defined(BOOST_ASSERT_CONFIG)
  #         error "Unknown EVC++ compiler version - please run the configure tests and report the results"
  #      else
  #         pragma message("Unknown EVC++ compiler version - please run the configure tests and report the results")
  #      endif
  #   endif
  # else
  #   if _MSC_VER < 1200
        // Note: Versions up to 7.0 aren't supported.
  #     define BOOST_COMPILER_VERSION 5.0
  #   elif _MSC_VER < 1300
  #     define BOOST_COMPILER_VERSION 6.0
  #   elif _MSC_VER < 1310
  #     define BOOST_COMPILER_VERSION 7.0
  #   elif _MSC_VER < 1400
  #     define BOOST_COMPILER_VERSION 7.1
  #   elif _MSC_VER < 1500
  #     define BOOST_COMPILER_VERSION 8.0
  #   elif _MSC_VER < 1600
  #     define BOOST_COMPILER_VERSION 9.0
  #   elif _MSC_VER < 1700
  #     define BOOST_COMPILER_VERSION 10.0
  #   elif _MSC_VER < 1800 
  #     define BOOST_COMPILER_VERSION 11.0
  #   elif _MSC_VER < 1900
  #     define BOOST_COMPILER_VERSION 12.0
  #   elif _MSC_VER < 1910
  #     define BOOST_COMPILER_VERSION 14.0
  #   elif _MSC_VER < 1920
  #     define BOOST_COMPILER_VERSION 14.1
  #   else
  #     define BOOST_COMPILER_VERSION _MSC_VER
  #   endif
  # endif
  
  #  define BOOST_COMPILER "Microsoft Visual C++ version " BOOST_STRINGIZE(BOOST_COMPILER_VERSION)
  #endif
  
  //
  // last known and checked version is 19.11.25547 (VC++ 2017.4):
  #if (_MSC_VER > 1911)
  #  if defined(BOOST_ASSERT_CONFIG)
  #     error "Boost.Config is older than your current compiler version."
  #  elif !defined(BOOST_CONFIG_SUPPRESS_OUTDATED_MESSAGE)
  #     pragma message("Info: Boost.Config is older than your compiler version - probably nothing bad will happen - but you may wish to look for an update Boost version.  Define BOOST_CONFIG_SUPPRESS_OUTDATED_MESSAGE to suppress this message.")
  #  endif
  #endif
  