--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/3rdparty/vmime/cmake/cmake-cxx11/Modules/CheckCXX11Features.cmake	Tue Aug 17 11:19:54 2021 +0200
@@ -0,0 +1,142 @@
+# - Check which parts of the C++11 standard the compiler supports
+#
+# When found it will set the following variables
+#
+#  CXX11_COMPILER_FLAGS         - the compiler flags needed to get C++11 features
+#
+#  HAS_CXX11_AUTO               - auto keyword
+#  HAS_CXX11_AUTO_RET_TYPE      - function declaration with deduced return types
+#  HAS_CXX11_CLASS_OVERRIDE     - override and final keywords for classes and methods
+#  HAS_CXX11_CONSTEXPR          - constexpr keyword
+#  HAS_CXX11_CSTDINT_H          - cstdint header
+#  HAS_CXX11_DECLTYPE           - decltype keyword
+#  HAS_CXX11_FUNC               - __func__ preprocessor constant
+#  HAS_CXX11_INITIALIZER_LIST   - initializer list
+#  HAS_CXX11_LAMBDA             - lambdas
+#  HAS_CXX11_LIB_REGEX          - regex library
+#  HAS_CXX11_LONG_LONG          - long long signed & unsigned types
+#  HAS_CXX11_NULLPTR            - nullptr
+#  HAS_CXX11_RVALUE_REFERENCES  - rvalue references
+#  HAS_CXX11_SIZEOF_MEMBER      - sizeof() non-static members
+#  HAS_CXX11_STATIC_ASSERT      - static_assert()
+#  HAS_CXX11_VARIADIC_TEMPLATES - variadic templates
+
+#=============================================================================
+# Copyright 2011,2012 Rolf Eike Beer <eike@sf-mail.de>
+# Copyright 2012 Andreas Weis
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+#
+# Each feature may have up to 3 checks, every one of them in it's own file
+# FEATURE.cpp              - example that must build and return 0 when run
+# FEATURE_fail.cpp         - example that must build, but may not return 0 when run
+# FEATURE_fail_compile.cpp - example that must fail compilation
+#
+# The first one is mandatory, the latter 2 are optional and do not depend on
+# each other (i.e. only one may be present).
+#
+
+if (NOT CMAKE_CXX_COMPILER_LOADED)
+    message(FATAL_ERROR "CheckCXX11Features modules only works if language CXX is enabled")
+endif ()
+
+cmake_minimum_required(VERSION 2.8.3)
+
+#
+### Check for needed compiler flags
+#
+include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag("-std=c++11" _HAS_CXX11_FLAG)
+if (NOT _HAS_CXX11_FLAG)
+    check_cxx_compiler_flag("-std=c++0x" _HAS_CXX0X_FLAG)
+endif ()
+
+if (_HAS_CXX11_FLAG)
+    set(CXX11_COMPILER_FLAGS "-std=c++11")
+elseif (_HAS_CXX0X_FLAG)
+    set(CXX11_COMPILER_FLAGS "-std=c++0x")
+endif ()
+
+function(cxx11_check_feature FEATURE_NAME RESULT_VAR)
+    if (NOT DEFINED ${RESULT_VAR})
+        set(_bindir "${CMAKE_CURRENT_BINARY_DIR}/cxx11_${FEATURE_NAME}")
+
+        set(_SRCFILE_BASE ${CMAKE_CURRENT_LIST_DIR}/CheckCXX11Features/cxx11-test-${FEATURE_NAME})
+        set(_LOG_NAME "\"${FEATURE_NAME}\"")
+        message(STATUS "Checking C++11 support for ${_LOG_NAME}")
+
+        set(_SRCFILE "${_SRCFILE_BASE}.cpp")
+        set(_SRCFILE_FAIL "${_SRCFILE_BASE}_fail.cpp")
+        set(_SRCFILE_FAIL_COMPILE "${_SRCFILE_BASE}_fail_compile.cpp")
+
+        if (CROSS_COMPILING)
+            try_compile(${RESULT_VAR} "${_bindir}" "${_SRCFILE}"
+                        COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            if (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+                try_compile(${RESULT_VAR} "${_bindir}_fail" "${_SRCFILE_FAIL}"
+                            COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            endif (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+        else (CROSS_COMPILING)
+            try_run(_RUN_RESULT_VAR _COMPILE_RESULT_VAR
+                    "${_bindir}" "${_SRCFILE}"
+                    COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            if (_COMPILE_RESULT_VAR AND NOT _RUN_RESULT_VAR)
+                set(${RESULT_VAR} TRUE)
+            else (_COMPILE_RESULT_VAR AND NOT _RUN_RESULT_VAR)
+                set(${RESULT_VAR} FALSE)
+            endif (_COMPILE_RESULT_VAR AND NOT _RUN_RESULT_VAR)
+            if (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+                try_run(_RUN_RESULT_VAR _COMPILE_RESULT_VAR
+                        "${_bindir}_fail" "${_SRCFILE_FAIL}"
+                         COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+                if (_COMPILE_RESULT_VAR AND _RUN_RESULT_VAR)
+                    set(${RESULT_VAR} TRUE)
+                else (_COMPILE_RESULT_VAR AND _RUN_RESULT_VAR)
+                    set(${RESULT_VAR} FALSE)
+                endif (_COMPILE_RESULT_VAR AND _RUN_RESULT_VAR)
+            endif (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+        endif (CROSS_COMPILING)
+        if (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL_COMPILE})
+            try_compile(_TMP_RESULT "${_bindir}_fail_compile" "${_SRCFILE_FAIL_COMPILE}"
+                        COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            if (_TMP_RESULT)
+                set(${RESULT_VAR} FALSE)
+            else (_TMP_RESULT)
+                set(${RESULT_VAR} TRUE)
+            endif (_TMP_RESULT)
+        endif (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL_COMPILE})
+
+        if (${RESULT_VAR})
+            message(STATUS "Checking C++11 support for ${_LOG_NAME}: works")
+        else (${RESULT_VAR})
+            message(STATUS "Checking C++11 support for ${_LOG_NAME}: not supported")
+        endif (${RESULT_VAR})
+        set(${RESULT_VAR} ${${RESULT_VAR}} CACHE INTERNAL "C++11 support for ${_LOG_NAME}")
+    endif (NOT DEFINED ${RESULT_VAR})
+endfunction(cxx11_check_feature)
+
+cxx11_check_feature("__func__" HAS_CXX11_FUNC)
+cxx11_check_feature("auto" HAS_CXX11_AUTO)
+cxx11_check_feature("auto_ret_type" HAS_CXX11_AUTO_RET_TYPE)
+cxx11_check_feature("class_override_final" HAS_CXX11_CLASS_OVERRIDE)
+cxx11_check_feature("constexpr" HAS_CXX11_CONSTEXPR)
+cxx11_check_feature("cstdint" HAS_CXX11_CSTDINT_H)
+cxx11_check_feature("decltype" HAS_CXX11_DECLTYPE)
+cxx11_check_feature("initializer_list" HAS_CXX11_INITIALIZER_LIST)
+cxx11_check_feature("lambda" HAS_CXX11_LAMBDA)
+cxx11_check_feature("long_long" HAS_CXX11_LONG_LONG)
+cxx11_check_feature("nullptr" HAS_CXX11_NULLPTR)
+cxx11_check_feature("regex" HAS_CXX11_LIB_REGEX)
+cxx11_check_feature("rvalue-references" HAS_CXX11_RVALUE_REFERENCES)
+cxx11_check_feature("sizeof_member" HAS_CXX11_SIZEOF_MEMBER)
+cxx11_check_feature("static_assert" HAS_CXX11_STATIC_ASSERT)
+cxx11_check_feature("variadic_templates" HAS_CXX11_VARIADIC_TEMPLATES)