Merge pull request #1624 from vikhik/master

Enforce using C++17 when linking against vsg in CMake

Author: robertosfield

INSTALL.md

@@ -170,22 +170,19 @@ To assist with setting up software to work with the VSG when you install the lib
 
 	find_package(vsg)
 
-To select C++17 compilation you'll need:
-
-	set_property(TARGET mytargetname PROPERTY CXX_STANDARD 17)
-
 To link your lib/application to required dependencies you'll need:
 
 	target_link_libraries(mytargetname vsg::vsg)
 
 This will tell CMake to set up all the appropriate include paths, libs and any definitions (such as the VSG_SHARED_LIBRARY #define that is required under Windows with shared library builds to select the correct declspec().)
 
+This will also tell CMake that your minimum C++ standard is 17.
+
 For example, a bare minimum CMakeLists.txt file to compile a single file application would be:
 
 	cmake_minimum_required(VERSION 3.7)
 	find_package(vsg REQUIRED)
 	add_executable(myapp "myapp.cpp")
-	set_property(TARGET myapp PROPERTY CXX_STANDARD 17)
 	target_link_libraries(myapp vsg::vsg)
 
 ### Using VSG provided cmake macros within your own projects
@@ -218,7 +215,6 @@ For example, a bare minimum CMakeLists.txt file adding the mentioned cmake targe
 	vsg_add_target_uninstall()
 
 	add_executable(myapp "myapp.cpp")
-	set_property(TARGET myapp PROPERTY CXX_STANDARD 17)
 	target_link_libraries(myapp vsg::vsg)
 
 ### Using VSG provided cmake macro to generate cmake support files

src/vsg/CMakeLists.txt

@@ -411,7 +411,7 @@ ASSIGN_SOURCE_GROUPS("Header Files" "${VSG_SOURCE_DIR}/include/vsg" ${HEADERS})
 set_property(TARGET vsg PROPERTY VERSION ${VSG_VERSION_MAJOR}.${VSG_VERSION_MINOR}.${VSG_VERSION_PATCH})
 set_property(TARGET vsg PROPERTY SOVERSION ${VSG_SOVERSION})
 set_property(TARGET vsg PROPERTY POSITION_INDEPENDENT_CODE ON)
-set_property(TARGET vsg PROPERTY CXX_STANDARD 17)
+target_compile_features(vsg PUBLIC cxx_std_17)
 if(WIN32)
     set_property(TARGET vsg PROPERTY RUNTIME_OUTPUT_NAME vsg-${VSG_SOVERSION})
 endif()