From 28cf80381e7284b0274a22d542016b92b9ad1a34 Mon Sep 17 00:00:00 2001
From: Andrey Astafyev <dev@246060.ru>
Date: Sun, 30 May 2021 20:31:10 +0300
Subject: [PATCH] =?UTF-8?q?=D0=92=D1=8B=D0=B1=D0=BE=D1=80=20=D0=B2=D0=B5?=
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 =?UTF-8?q?=D1=82=D1=80=D0=B0=201.5=20-=2011,=20=D0=B8=D0=BD=D0=B0=D1=87?=
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---
 CMLibCompilerFlags.cmake | 69 ++++++++++++++++++++++++++++++----------
 1 file changed, 52 insertions(+), 17 deletions(-)

diff --git a/CMLibCompilerFlags.cmake b/CMLibCompilerFlags.cmake
index 7afb7c6..57d72da 100644
--- a/CMLibCompilerFlags.cmake
+++ b/CMLibCompilerFlags.cmake
@@ -19,33 +19,68 @@ macro(CHECK_ENABLE_CXX_FLAG flag)
   unset(CHECK_CXX_FLAG CACHE)
 endmacro()
 
-if(LSB_DISTRIBUTOR_ID STREQUAL "AstraLinuxSE" AND LSB_CODENAME STREQUAL "smolensk" AND LSB_RELEASE STREQUAL
-                                                                                       "1.5")
+function(cmlib_set_cxx_standard version)
+
+  # Выбор стандарта по умолчанию (можно переопределить в проекте)
+  set(CMAKE_CXX_STANDARD_REQUIRED YES)
+
+  if(version STREQUAL "11")
+    set(CMAKE_CXX_STANDARD 11)
+    set(CMAKE_CXX_EXTENSIONS YES)
+  endif()
+
+  if(version STREQUAL "14")
+    set(CMAKE_CXX_STANDARD 14)
+    set(CMAKE_CXX_EXTENSIONS YES)
+  endif()
+
+  if(version STREQUAL "17")
+    if(${CMAKE_VERSION} VERSION_LESS "3.10.0")
+      check_cxx_compiler_flag(-std=gnu++17 HAVE_FLAG_STD_GNUXX17)
+      if(HAVE_FLAG_STD_GNUXX17)
+        add_compile_options("-std=gnu++17")
+      else()
+        check_cxx_compiler_flag(-std=gnu++1z HAVE_FLAG_STD_GNUXX1Z)
+        if(HAVE_FLAG_STD_GNUXX1Z)
+          add_compile_options("-std=gnu++1z")
+        else()
+          check_cxx_compiler_flag(-std=c++17 HAVE_FLAG_STD_CXX17)
+          if(HAVE_FLAG_STD_CXX17)
+            add_compile_options("-std=c++17")
+          else()
+            check_cxx_compiler_flag(-std=c++1z HAVE_FLAG_STD_CXX1Z)
+            if(HAVE_FLAG_STD_CXX1Z)
+              add_compile_options("-std=c++1z")
+            endif()
+          endif()
+        endif()
+      endif()
+    else()
+      set(CMAKE_CXX_STANDARD 17)
+      set(CMAKE_CXX_EXTENSIONS YES)
+    endif()
+  endif()
+endfunction()
+
+# cmake-format: off
+if(LSB_DISTRIBUTOR_ID STREQUAL "AstraLinuxSE" AND
+   LSB_CODENAME       STREQUAL "smolensk" AND
+   LSB_RELEASE        STREQUAL "1.5")
+# cmake-format: on
+  cmlib_set_cxx_standard(11)
+
   set(_CMAKE_TOOLCHAIN_PREFIX "x86_64-linux-gnu-")
   set(_CMAKE_TOOLCHAIN_SUFFIX "-4.7")
   set(_CMAKE_TOOLCHAIN_LOCATION} "/usr/bin")
 else()
+  cmlib_set_cxx_standard(17)
+
   # -Wshadow gives a lot of false positives with GCC 4.7.2 in Astra Linux 1.5
   if(CMAKE_CXX_COMPILER_IS_GCC)
     check_enable_cxx_flag(-Wshadow)
   endif()
 endif()
 
-# Выбор стандарта по умолчанию (можно переопределить в проекте)
-set(CMAKE_CXX_STANDARD_REQUIRED YES)
-
-check_cxx_compiler_flag(-std=c++14 HAVE_FLAG_STD_CXX14)
-if(HAVE_FLAG_STD_CXX14)
-  set(CMAKE_CXX_STANDARD 14)
-  check_cxx_compiler_flag(-std=gnu++14 HAVE_FLAG_STD_GNUXX14)
-  if(HAVE_FLAG_STD_GNUXX14)
-    set(CMAKE_CXX_EXTENSIONS YES)
-  endif()
-else()
-  set(CMAKE_CXX_STANDARD 11)
-  set(CMAKE_CXX_EXTENSIONS YES)
-endif()
-
 # Common configuration for GCC, clang and Intel.
 if(CMAKE_CXX_COMPILER_IS_CLANG OR CMAKE_CXX_COMPILER_IS_INTEL OR CMAKE_CXX_COMPILER_IS_GCC)
   if(CMLIB_WARNING_FLAGS AND CMAKE_BUILD_TYPE STREQUAL "Debug")