1 // Copyright 2023 The Chromium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_MACROS_IS_EMPTY_H_ 6 #define BASE_MACROS_IS_EMPTY_H_ 7 8 // A macro that substitutes with 1 if called without arguments, otherwise 0. 9 #define BASE_IS_EMPTY(...) BASE_INTERNAL_IS_EMPTY_EXPANDED(__VA_ARGS__) 10 #define BASE_INTERNAL_IS_EMPTY_EXPANDED(...) \ 11 BASE_INTERNAL_IS_EMPTY_INNER(_, ##__VA_ARGS__) 12 #define BASE_INTERNAL_IS_EMPTY_INNER(...) \ 13 BASE_INTERNAL_IS_EMPTY_INNER_EXPANDED(__VA_ARGS__, 0, 1) 14 #define BASE_INTERNAL_IS_EMPTY_INNER_EXPANDED(e0, e1, is_empty, ...) is_empty 15 16 #endif // BASE_MACROS_IS_EMPTY_H_ 17