TODO Enable cognitive complexity.

Some of the functions are quite long and complex.
This change adds some Clippy warnings that will find them.

The warnings can be enabled temporarily
while working on refactoring. They should be enabled
permanently once refactoring is completed.

Author: peso

src/lib.rs

@@ -7,6 +7,15 @@
 //! 2. Lay out the graph structure according to the branching model (See [graph])
 //! 3. Render the layout to text or SVG (See [mod@print])
 
+/* TODO git-graph has some complex functions, which make it hard to
+understand and modify the code. The code should be made simpler
+so the following warnings can be enabled without triggering.
+
+// Configure clippy to look for complex functions
+#![warn(clippy::cognitive_complexity)]
+#![warn(clippy::too_many_lines)]
+*/
+
 use git2::Repository;
 use std::path::Path;