1 // Copyright 2024 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 15 // Macros for working with arguments to function-like macros. 16 #pragma once 17 18 #include "pw_preprocessor/arguments.h" 19 #include "pw_preprocessor/internal/apply_macros.h" 20 21 /// Repeatedly applies the given macro for each argument provided. The given 22 /// macro expands to accept an index value of the current argument, the 23 /// forwarded argument provided, and the current argument. The forwarded 24 /// argument is used in every macro call. The separator expands to accept the 25 /// index argument as well as the forwarded argument. The last separator is 26 /// omitted. 27 /// 28 /// The example below shows how this macro expands, based on a pre-defined 29 /// macro and separator. The statement `PW_APPLY(MACRO, SEP, ARG, a0, a1)` 30 /// expands to: 31 /// 32 /// @code{.cpp} 33 /// MACRO(0, ARG, a0) SEP(0, ARG) MACRO(1, ARG, a1) 34 /// @endcode 35 #define PW_APPLY(macro, separator, forwarded_arg, ...) \ 36 _PW_APPLY(_PW_PASTE2(_PW_APL, PW_FUNCTION_ARG_COUNT(__VA_ARGS__)), \ 37 macro, \ 38 separator, \ 39 forwarded_arg, \ 40 PW_DROP_LAST_ARG_IF_EMPTY(__VA_ARGS__)) 41 42 #define _PW_APPLY(function, macro, separator, forwarded_arg, ...) \ 43 function(macro, separator, forwarded_arg, __VA_ARGS__) 44