Use [[fallthrough]] in some switch statements

src/beast/extras/beast/unit_test/match.hpp

@@ -110,7 +110,6 @@ selector::operator()(suite_info const& s)
 
     case all:
     default:
-        // fall through
         break;
     };
 

src/ripple/app/ledger/OpenLedger.h

@@ -248,6 +248,7 @@ OpenLedger::apply (Application& app, OpenView& view,
             {
             case Result::success:
                 ++changes;
+                [[fallthrough]];
             case Result::failure:
                 iter = retries.erase (iter);
                 break;

src/ripple/app/ledger/impl/InboundLedger.cpp

@@ -475,7 +475,7 @@ void InboundLedger::done ()
         {
         case Reason::SHARD:
             app_.getShardStore()->setStored(mLedger);
-            // TODO c++17: [[fallthrough]]
+            [[fallthrough]];
         case Reason::HISTORY:
             app_.getInboundLedgers().onLedgerFetched();
             break;

src/ripple/app/tx/impl/apply.cpp

@@ -90,10 +90,10 @@ forceValidity(HashRouter& router, uint256 const& txid,
     {
     case Validity::Valid:
         flags |= SF_LOCALGOOD;
-        // fall through
+        [[fallthrough]];
     case Validity::SigGoodOnly:
         flags |= SF_SIGGOOD;
-        // fall through
+        [[fallthrough]];
     case Validity::SigBad:
         // would be silly to call directly
         break;

src/ripple/app/tx/impl/applySteps.cpp

@@ -215,7 +215,7 @@ invoke_calculateConsequences(STTx const& tx)
     case ttTRUST_SET:            return invoke_calculateConsequences<SetTrust>(tx);
     case ttAMENDMENT:
     case ttFEE:
-        // fall through to default
+        [[fallthrough]];
     default:
         assert(false);
         return { TxConsequences::blocker, Transactor::calculateFeePaid(tx),

src/ripple/basics/impl/Log.cpp

@@ -216,6 +216,7 @@ Logs::fromSeverity (beast::severities::Severity level)
 
     default:
         assert(false);
+        [[fallthrough]];
     case kFatal:
         break;
     }
@@ -236,6 +237,7 @@ Logs::toSeverity (LogSeverity level)
     case lsERROR:   return kError;
     default:
         assert(false);
+        [[fallthrough]];
     case lsFATAL:
         break;
     }
@@ -306,6 +308,7 @@ Logs::format (std::string& output, std::string const& message,
     case kError:    output += "ERR "; break;
     default:
         assert(false);
+        [[fallthrough]];
     case kFatal:    output += "FTL "; break;
     }