Install yasnippet and vala-snippets packages

elpa/yasnippet-20160924.2001/snippets/c++-mode/.yas-setup.el

@@ -0,0 +1,10 @@
+(defun yas-c++-class-name (str)
+  "Search for a class name like `DerivedClass' in STR
+(which may look like `DerivedClass : ParentClass1, ParentClass2, ...')
+
+If found, the class name is returned, otherwise STR is returned"
+  (yas-substr str "[^: ]*"))
+
+(defun yas-c++-class-method-declare-choice ()
+  "Choose and return the end of a C++11 class method declaration"
+  (yas-choose-value '(";" " = default;" " = delete;")))