New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/mwm_diff/diff.hpp

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <string>
+
+namespace base
+{
+class Cancellable;
+}
+
+namespace generator
+{
+namespace mwm_diff
+{
+enum class DiffApplicationResult
+{
+  Ok,
+  Failed,
+  Cancelled,
+};
+
+// Makes a diff that, when applied to the mwm at |oldMwmPath|, will
+// result in the mwm at |newMwmPath|. The diff is stored at |diffPath|.
+// It is assumed that the files at |oldMwmPath| and |newMwmPath| are valid mwms.
+// Returns true on success and false on failure.
+bool MakeDiff(std::string const & oldMwmPath, std::string const & newMwmPath,
+              std::string const & diffPath);
+
+// Applies the diff at |diffPath| to the mwm at |oldMwmPath|. The resulting
+// mwm is stored at |newMwmPath|.
+// It is assumed that the file at |oldMwmPath| is a valid mwm and the file
+// at |diffPath| is a valid mwmdiff.
+// The application process can be stopped via |cancellable| in which case
+// it is up to the caller to clean the partially written file at |diffPath|.
+DiffApplicationResult ApplyDiff(std::string const & oldMwmPath, std::string const & newMwmPath,
+                                std::string const & diffPath,
+                                base::Cancellable const & cancellable);
+
+std::string DebugPrint(DiffApplicationResult const & result);
+}  // namespace mwm_diff
+}  // namespace generator