Require CMake 3.10 and use CMAKE_CXX_STANDARD

Removes the need to add -std= flags manually. CMake 3.10 is available
in Ubuntu 18.04, which is the oldest LTS version we support.

CMakeLists.txt

@@ -1,7 +1,7 @@
 ########################################
 # General setup
 #
-cmake_minimum_required(VERSION 3.5.0)
+cmake_minimum_required(VERSION 3.10)
 set(CMAKE_OSX_ARCHITECTURES "x86_64")
 # Minimum OS X version.
 # This is inserted into the Info.plist as well.

Source/Android/app/build.gradle

@@ -60,6 +60,7 @@ android {
     externalNativeBuild {
         cmake {
             path "../../../CMakeLists.txt"
+            version "3.10.2"
         }
     }
 

Source/CMakeLists.txt

@@ -9,21 +9,9 @@ if(CMAKE_SYSTEM_NAME MATCHES "Windows")
   add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
 endif()
 
-if(CMAKE_C_COMPILER_ID MATCHES "MSVC")
-  # enable the latest C++ standard feature set,
-  # and also disable MSVC specific extensions
-  # to be even more standards compliant.
-  check_and_add_flag(CPPLATEST /std:c++latest)
-  check_and_add_flag(STANDARD_COMPLIANCE /permissive-)
-else()
-  # Enable C++17
-  # CMAKE_CXX_STANDARD cannot be used because it requires cmake 3.8+.
-  check_and_add_flag(CXX17 -std=c++17)
-  if(NOT FLAG_CXX_CXX17)
-    # Fall back to -std=c++1z
-    check_and_add_flag(CXX1Z -std=c++1z)
-  endif()
-endif()
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 # These aren't actually needed for C11/C++11
 # but some dependencies require them (LLVM, libav).