Merge "Initial commit: cframework. Longbow and Libparc" into cframework/master

1 files changed, 49 insertions, 0 deletions

diff --git a/libparc/parc/algol/parc_CMacro.h b/libparc/parc/algol/parc_CMacro.h
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+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @file parc_CMacro.h
+ * @ingroup Macro
+ * @brief Utility C-Macros
+ *
+ * CMacro contains a set of utility macros for doing complicated macro processing
+ *
+ */
+#ifndef libparc_parc_CMacro_h
+#define libparc_parc_CMacro_h
+
+/**
+ * parcCMacro_ThridParam expands to the "3rd" input parameter whatever that may be. It is a part
+ * of the c-macro trick for implement a macro If-Else switch. If the first argument expands
+ * to a comma then this macro expands to the second parameter, otherwise it expands to the 3rd parameter.
+ */
+#define parcCMacro_ThirdParam(A, B, C, ...) C
+
+/**
+ * parcCMacro_IfElse is a c-macro trick for implementing a macro If-Else switch.
+ * It uses parcCMacro_ThirdParam to select between A or B depending on whether __VA_ARGS__ expands to a comma.
+ */
+#define parcCMacro_IfElse(A, B, ...) parcCMacro_ThirdParam(__VA_ARGS__, A, B, NOOP)
+
+/** \cond */
+#define _parcCMacro_Cat_(A, B) A ## B
+/** \endcond */
+
+/**
+ * parcCMacro_Cat combines two strings into a single token.
+ */
+#define parcCMacro_Cat(A, B) _parcCMacro_Cat_(A, B)
+
+#endif //libparc_parc_CMacro_h