fix compilation error / clang warnings

lib/index/mu-indexer.hh

@@ -25,7 +25,7 @@
 
 namespace Mu {
 
-struct Store;
+class Store;
 
 /// An object abstracting the index process.
 class Indexer {

lib/mu-query.cc

@@ -200,7 +200,7 @@ get_query (MuQuery *mqx, const char* searchexpr, bool raw, GError **err) try {
 	Mu::WarningVec warns;
 	const auto tree = Mu::parse (searchexpr, warns,
 				      std::make_unique<MuProc>(mqx->db()));
-	for (const auto w: warns)
+	for (auto&& w: warns)
 		std::cerr << w << std::endl;
 
 	return Mu::xapian_query (tree);
@@ -514,7 +514,7 @@ mu_query_internal (MuQuery *self, const char *searchexpr,
 		ss << tree;
 
 		if (warn) {
-			for (const auto w: warns)
+			for (auto&& w: warns)
 				std::cerr << w << std::endl;
 		}
 

lib/query/mu-xapian.cc

@@ -79,7 +79,7 @@ xapian_query_value (const Mu::Tree& tree)
 		return make_query(v, parts.front(), true/*maybe-wildcard*/);
 
 	std::vector<Xapian::Query> phvec;
-	for (const auto p: parts)
+	for (const auto& p: parts)
 		phvec.emplace_back(make_query(v, p, false/*no wildcards*/));
 
         return Xapian::Query (Xapian::Query::OP_PHRASE, phvec.begin(), phvec.end());

lib/query/test-tokenizer.cc

@@ -133,7 +133,7 @@ static void
 test_to_string ()
 {
 	std::stringstream ss;
-	for (const auto t: tokenize ("foo and bar xor not cuux or fnorb"))
+	for (auto&& t: tokenize ("foo and bar xor not cuux or fnorb"))
 		ss << t << ' ';
 
 	g_assert_true (ss.str() ==

lib/utils/mu-logger.cc

@@ -32,7 +32,6 @@
 
 using namespace Mu;
 
-constexpr auto        MuLogDomain      = "mu";
 static bool           MuLogInitialized = false;
 static Mu::LogOptions MuLogOptions;
 static std::ofstream  MuStream;

lib/utils/mu-sexp.hh

@@ -176,8 +176,8 @@ struct Sexp {
                 size_t empty() const { return seq_.empty(); }
 
         private:
-                friend class Sexp;
-                Seq          seq_;
+                friend struct Sexp;
+                Seq           seq_;
         };
 
         /**