ircd: Various string_view conversion fixes.

include/ircd/string_view.h

@@ -47,6 +47,19 @@ struct ircd::string_view
 		return !empty();
 	}
 
+	/// CAREFUL. THIS IS ON PURPOSE. By relaxing this conversion we're reducing
+	/// the amount of explicit std::string() pollution when calling out to code
+	/// which doesn't support string_view *yet* (keyword: yet). When it does
+	/// support string_view then this conversion won't happen, and we don't
+	/// have to change anything in our code. The price here is that an
+	/// occasional regression analysis on where these conversions are occurring
+	/// should be periodically performed to make sure there are no unwanted
+	/// silent accidents.
+	operator std::string() const
+	{
+		return std::string(cbegin(), cend());
+	}
+
 	/// (non-standard) When data() != nullptr we consider the string defined
 	/// downstream in this project wrt JS/JSON. This is the bit of information
 	/// we're deciding on for defined|undefined. If this string_view is
@@ -169,7 +182,7 @@ struct ircd::string_view
 //	:std::string_view{start, size}
 //	{}
 
-	explicit string_view(const std::string &string)
+	string_view(const std::string &string)
 	:std::string_view{string.data(), string.size()}
 	{}
 

ircd/db.cc

@@ -223,11 +223,16 @@ void
 ircd::db::init_test_direct_io()
 try
 {
-	if(fs::direct_io_support(direct_io_test_file_path()))
+	const auto test_file_path
+	{
+		direct_io_test_file_path()
+	};
+
+	if(fs::direct_io_support(test_file_path))
 		log::debug
 		{
 			log, "Detected Direct-IO works by opening test file at `%s'",
-			direct_io_test_file_path()
+			test_file_path
 		};
 	else
 		log::warning
@@ -256,7 +261,12 @@ ircd::db::direct_io_test_file_path()
 		fs::get(fs::DB)
 	};
 
-	return fs::make_path({dbdir, "SUPPORTS_DIRECT_IO"s});
+	const std::string parts[]
+	{
+		dbdir, "SUPPORTS_DIRECT_IO"s
+	};
+
+	return fs::make_path(parts);
 }
 
 void
@@ -8792,10 +8802,12 @@ ircd::db::path(const string_view &name,
 		fs::get(fs::DB)
 	};
 
-	return fs::make_path(
+	const string_view parts[]
 	{
 		prefix, name, lex_cast(checkpoint)
-	});
+	};
+
+	return fs::make_path(parts);
 }
 
 std::pair<ircd::string_view, uint64_t>

ircd/mods.cc

@@ -291,7 +291,7 @@ try
 		ret->header->version,
 		!ret->description().empty()?
 			ret->description():
-			"<no description>"s
+			"<no description>"_sv
 	};
 
 	return ret;