Tutorial: Improve Step 9

* Move USE_MYMATH from configured header to target_compile_definitions

Help/guide/tutorial/MultiPackage/MathFunctions/CMakeLists.txt

@@ -13,6 +13,8 @@ target_include_directories(MathFunctions
 option(USE_MYMATH "Use tutorial provided math implementation" ON)
 if(USE_MYMATH)
 
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
   # first we add the executable that generates the table
   add_executable(MakeTable MakeTable.cxx)
 
@@ -34,6 +36,7 @@ if(USE_MYMATH)
                              ${CMAKE_CURRENT_BINARY_DIR}
                              )
 
+  # state that SqrtLibrary need PIC when the default is shared libraries
   set_target_properties(SqrtLibrary PROPERTIES
                         POSITION_INDEPENDENT_CODE ${BUILD_SHARED_LIBS}
                         )
@@ -41,8 +44,6 @@ if(USE_MYMATH)
   target_link_libraries(MathFunctions PRIVATE SqrtLibrary)
 endif()
 
-target_compile_definitions(MathFunctions PRIVATE "$<$<BOOL:${USE_MYMATH}>:USE_MYMATH>")
-
 # define the symbol stating we are using the declspec(dllexport) when
 # building on windows
 target_compile_definitions(MathFunctions PRIVATE "EXPORTING_MYMATH")

Help/guide/tutorial/MultiPackage/tutorial.cxx

@@ -1,6 +1,5 @@
 // A simple program that computes the square root of a number
 #include <iostream>
-#include <sstream>
 #include <string>
 
 #include "MathFunctions.h"