Overhaul store subclassing

We embrace virtual the rest of the way, and get rid of the
`assert(false)` 0-param constructors.

We also list config base classes first, so the constructor order is
always:

  1. all the configs
  2. all the stores

Each in the same order

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index 9d2a89f96..0a3afcd51 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -15,7 +15,7 @@ struct HttpBinaryCacheStoreConfig : virtual BinaryCacheStoreConfig
     const std::string name() override { return "Http Binary Cache Store"; }
 };
 
-class HttpBinaryCacheStore : public BinaryCacheStore, public HttpBinaryCacheStoreConfig
+class HttpBinaryCacheStore : public virtual HttpBinaryCacheStoreConfig, public virtual BinaryCacheStore
 {
 private:
 
@@ -36,6 +36,9 @@ public:
         const Path & _cacheUri,
         const Params & params)
         : StoreConfig(params)
+        , BinaryCacheStoreConfig(params)
+        , HttpBinaryCacheStoreConfig(params)
+        , Store(params)
         , BinaryCacheStore(params)
         , cacheUri(scheme + "://" + _cacheUri)
     {