input/Error: new library providing IsFileNotFound()

Makefile.am

@@ -1293,6 +1293,7 @@ endif
 #
 
 libinput_a_SOURCES = \
+	src/input/Error.cxx src/input/Error.hxx \
 	src/input/Init.cxx src/input/Init.hxx \
 	src/input/Registry.cxx src/input/Registry.hxx \
 	src/input/Open.cxx \

src/input/Error.cxx

+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "Error.hxx"
+#include "system/Error.hxx"
+
+bool
+IsFileNotFound(std::exception_ptr ep)
+{
+	try {
+		std::rethrow_exception(ep);
+	} catch (const std::system_error &e) {
+		return IsFileNotFound(e);
+	} catch (...) {
+	}
+
+	return false;
+}
+

src/input/Error.hxx

+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef INPUT_ERROR_HXX
+#define INPUT_ERROR_HXX
+
+#include "check.h"
+#include "Compiler.h"
+
+#include <exception>
+
+/**
+ * Was this exception thrown because the requested file does not
+ * exist?  This function attempts to recognize exceptions thrown by
+ * various input plugins.
+ */
+gcc_pure
+bool
+IsFileNotFound(std::exception_ptr e);
+
+#endif