Install yasnippet and vala-snippets packages

elpa/yasnippet-20160924.2001/snippets/c++-mode/operator=

@@ -0,0 +1,14 @@
+# -*- mode: snippet -*-
+# name: operator=
+# key: =
+# where this is a reference to myself
+# group: operator overloading
+# --
+${1:MyClass}& $1::operator=(const $1 &rhs)
+{
+    // Check for self-assignment!
+    if (this == &rhs)
+      return *this;
+    $0
+    return *this;
+}