filter/chain: pass std::string_view to filter_chain_append()

src/filter/LoadChain.cxx

@@ -27,10 +27,13 @@
 
 static void
 filter_chain_append_new(PreparedFilter &chain, FilterFactory &factory,
-			const char *template_name)
+			std::string_view template_name)
 {
 	filter_chain_append(chain, template_name,
-			    factory.MakeFilter(template_name));
+			    /* unfortunately, MakeFilter() wants a
+			       null-terminated string, so we need to
+			       copy it here */
+			    factory.MakeFilter(std::string(template_name).c_str()));
 }
 
 void
@@ -42,7 +45,6 @@ filter_chain_parse(PreparedFilter &chain,
 		if (i.empty())
 			continue;
 
-		const std::string name(i);
-		filter_chain_append_new(chain, factory, name.c_str());
+		filter_chain_append_new(chain, factory, i);
 	}
 }

src/filter/plugins/ChainFilterPlugin.cxx

@@ -76,7 +76,7 @@ class PreparedChainFilter final : public PreparedFilter {
 		const std::string name;
 		std::unique_ptr<PreparedFilter> filter;
 
-		Child(const char *_name,
+		Child(std::string_view _name,
 		      std::unique_ptr<PreparedFilter> _filter)
 			:name(_name), filter(std::move(_filter)) {}
 
@@ -89,7 +89,7 @@ class PreparedChainFilter final : public PreparedFilter {
 	std::list<Child> children;
 
 public:
-	void Append(const char *name,
+	void Append(std::string_view name,
 		    std::unique_ptr<PreparedFilter> filter) noexcept {
 		children.emplace_back(name, std::move(filter));
 	}
@@ -175,7 +175,7 @@ filter_chain_new() noexcept
 }
 
 void
-filter_chain_append(PreparedFilter &_chain, const char *name,
+filter_chain_append(PreparedFilter &_chain, std::string_view name,
 		    std::unique_ptr<PreparedFilter> filter) noexcept
 {
 	auto &chain = (PreparedChainFilter &)_chain;

src/filter/plugins/ChainFilterPlugin.hxx

@@ -28,6 +28,7 @@
 #define MPD_FILTER_CHAIN_HXX
 
 #include <memory>
+#include <string_view>
 
 class PreparedFilter;
 
@@ -45,7 +46,7 @@ filter_chain_new() noexcept;
  * @param filter the filter to be appended to #chain
  */
 void
-filter_chain_append(PreparedFilter &chain, const char *name,
+filter_chain_append(PreparedFilter &chain, std::string_view name,
 		    std::unique_ptr<PreparedFilter> filter) noexcept;
 
 #endif