config/Param: overload GetPath() throwing exception

src/config/Param.cxx

@@ -23,6 +23,8 @@
 #include "fs/AllocatedPath.hxx"
 #include "util/Error.hxx"
 
+#include <stdexcept>
+
 ConfigParam::ConfigParam(const char *_value, int _line)
 	:next(nullptr), value(_value), line(_line), used(false) {}
 
@@ -41,3 +43,15 @@ ConfigParam::GetPath(Error &error) const
 	return path;
 
 }
+
+AllocatedPath
+ConfigParam::GetPath() const
+{
+	Error error;
+	auto path = ParsePath(value.c_str(), error);
+	if (gcc_unlikely(path.IsNull()))
+		throw std::runtime_error(error.GetMessage());
+
+	return path;
+
+}

src/config/Param.hxx

@@ -72,6 +72,15 @@ struct ConfigParam {
 	 * AllocatedPath::Null() and sets the error.
 	 */
 	AllocatedPath GetPath(Error &error) const;
+
+	/**
+	 * Parse the value as a path.  If there is a tilde prefix, it
+	 * is expanded.
+	 *
+	 * Throws #std::runtime_error on error.
+	 */
+	gcc_pure
+	AllocatedPath GetPath() const;
 };
 
 #endif