Add final attribute to many classes

In some cases this can offer better optimization, via devirtualization.
And it lets the user know the class is not intended for derivation.

Some discussion in GH #402

1 files changed, 1 insertions, 1 deletions

diff --git a/src/lib/stream/chacha/chacha.h b/src/lib/stream/chacha/chacha.h
index df6e1c9c0..92f8ef035 100644
--- a/src/lib/stream/chacha/chacha.h
+++ b/src/lib/stream/chacha/chacha.h
@@ -15,7 +15,7 @@ namespace Botan {
 /**
 * DJB's ChaCha (http://cr.yp.to/chacha.html)
 */
-class BOTAN_DLL ChaCha : public StreamCipher
+class BOTAN_DLL ChaCha final : public StreamCipher
    {
    public:
       void cipher(const byte in[], byte out[], size_t length) override;