Some comments to Qt5 sample.

test cases/frameworks/4 qt5/meson.build

@@ -3,9 +3,9 @@ project('qt5 build test', 'cxx')
 qt5dep = find_dep('qt5', modules : 'Widgets', required : true)
 
 q5exe = executable('qt5test',
-sources : ['main.cpp', 'mainWindow.cpp'],
-moc_headers : ['mainWindow.h'],
-ui_files : 'mainWindow.ui',
+sources : ['main.cpp', 'mainWindow.cpp'], # Sources that don't need preprocessing.
+moc_headers : ['mainWindow.h'], # These need to be fed through the moc tool before use. 
+ui_files : 'mainWindow.ui', # XML files that need to be compiled with the uic tol.
 deps : qt5dep)
 
 add_test('qt5test', q5exe)