_LIBCPP_INLINE_VISIBILITY path extension() const { return string_type(__extension()); }
// query
- _LIBCPP_INLINE_VISIBILITY bool empty() const _NOEXCEPT { return __pn_.empty(); }
+ _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+ bool empty() const _NOEXCEPT { return __pn_.empty(); }
_LIBCPP_INLINE_VISIBILITY bool has_root_name() const { return !__root_name().empty(); }
_LIBCPP_INLINE_VISIBILITY bool has_root_directory() const { return !__root_directory().empty(); }
--- /dev/null
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <experimental/filesystem>
+
+// class path
+
+// bool empty() const noexcept;
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+#include <experimental/filesystem>
+
+#include "test_macros.h"
+
+int main ()
+{
+ std::experimental::filesystem::path c;
+ c.empty(); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+}