Update to minimum CMake 3.5

And modernise some examples.

02-sub-projects/A-basic/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.0)
+cmake_minimum_required (VERSION 3.5)
 
 project(subprojects)
 

02-sub-projects/A-basic/README.adoc

@@ -145,7 +145,7 @@ is added as a dependency.
 ----
 target_link_libraries(subbinary
     PUBLIC
-    sublibrary1
+        sublibrary1
 )
 ----
 
@@ -164,7 +164,7 @@ To reference the alias, just it as follows:
 [source,cmake]
 ----
 target_link_libraries(subbinary
-    sublibrary1
+    sub::lib2
 )
 ----
 

02-sub-projects/A-basic/subbinary/CMakeLists.txt

@@ -1,11 +1,7 @@
 project(subbinary)
 
-set(SOURCES
-    main.cpp
-)
-
 # Create the executable
-add_executable(${PROJECT_NAME} ${SOURCES})
+add_executable(${PROJECT_NAME} main.cpp)
 
 # Link the static library from subproject1 using it's alias sub::lib1
 # Link the header only library from subproject2 using it's alias sub::lib2

02-sub-projects/A-basic/sublibrary1/CMakeLists.txt

@@ -1,13 +1,8 @@
 # Set the project name
 project (sublibrary1)
 
-# Create a sources variable with a link to all cpp files to compile
-set(SOURCES
-    src/sublib1.cpp
-)
-
 # Add a library with the above sources
-add_library(${PROJECT_NAME} ${SOURCES})
+add_library(${PROJECT_NAME} src/sublib1.cpp)
 add_library(sub::lib1 ALIAS ${PROJECT_NAME})
 
 target_include_directories( ${PROJECT_NAME}