Merge branch 'pputils.CxxUtils-20240507' into 'main'

CxxUtils: Add some preprocessor utils.

See merge request !71221

Control/CxxUtils/CMakeLists.txt

@@ -169,7 +169,7 @@ foreach( test sincos_test ArrayScanner_test Arrayrep_test
       FPControl_test LockedPointer_test nodiscard_test span_test
       reverse_wrapper_test atomic_bounded_decrement_test
       releasing_iterator_test SizedUInt_test UIntConv_test starts_with_test
-      normalizeFunctionName_test )
+      normalizeFunctionName_test pputils_test )
    atlas_add_test( ${test}
       SOURCES test/${test}.cxx
       LINK_LIBRARIES CxxUtils TestTools ${Boost_LIBRARIES})

Control/CxxUtils/CxxUtils/pputils.h

+// This file's extension implies that it's C, but it's really -*- C++ -*-.
+/*
+ * Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration.
+ */
+/**
+ * @file CxxUtils/pputils.h
+ * @author scott snyder <snyder@bnl.gov>
+ * @date May, 2024
+ * @brief Preprocessor utilities.
+ *
+ * Given an argument list of arbitrary length, @c CXXUTILS_PP_FIRST returns
+ * a comma followed by the first argument if it exists; otherwise,
+ * it expands to nothing.  @c CXXUTILS_PP_SECOND does the same thing
+ * for the second argument, and so on through @CXXUTILS_PP_FIFTH.
+ *
+ * That is:
+ *@code
+ *  CXXUTILS_PP_FIRST(a, b, c)  -> , a
+ *  CXXUTILS_PP_FIRST()         ->
+ *  CXXUTILS_PP_SECOND(a, b, c) -> , b
+ *  CXXUTILS_PP_SECOND(a)       ->
+ @endcode
+ *
+ * @c CXXUTILS_PP_ARG1 through @c CXXUTILS_PP_ARG5 are also available
+ * as synonyms that may be more useful if these are used through the
+ * expansion of other macros.
+ */
+
+
+#ifndef CXXUTILS_PPARGS_H
+#define CXXUTILS_PPARGS_H
+
+
+#define CXXUTILS_PP_FIRST(...) CXXUTILS_PP_ARG1(__VA_ARGS__)
+#define CXXUTILS_PP_ARG1(...) __VA_OPT__(CXXUTILS_PP_ARG1_(__VA_ARGS__))
+#define CXXUTILS_PP_ARG1_(A, ...) , A
+
+#define CXXUTILS_PP_SECOND(...) CXXUTILS_PP_ARG2(__VA_ARGS__)
+#define CXXUTILS_PP_ARG2(...) __VA_OPT__(CXXUTILS_PP_ARG2_(__VA_ARGS__))
+#define CXXUTILS_PP_ARG2_(A, ...) CXXUTILS_PP_ARG1(__VA_ARGS__)
+
+#define CXXUTILS_PP_THIRD(...) CXXUTILS_PP_ARG3(__VA_ARGS__)
+#define CXXUTILS_PP_ARG3(...) __VA_OPT__(CXXUTILS_PP_ARG3_(__VA_ARGS__))
+#define CXXUTILS_PP_ARG3_(A, ...) CXXUTILS_PP_ARG2(__VA_ARGS__)
+
+#define CXXUTILS_PP_FOURTH(...) CXXUTILS_PP_ARG4(__VA_ARGS__)
+#define CXXUTILS_PP_ARG4(...) __VA_OPT__(CXXUTILS_PP_ARG4_(__VA_ARGS__))
+#define CXXUTILS_PP_ARG4_(A, ...) CXXUTILS_PP_ARG3(__VA_ARGS__)
+
+#define CXXUTILS_PP_FIFTH(...) CXXUTILS_PP_ARG5(__VA_ARGS__)
+#define CXXUTILS_PP_ARG5(...) __VA_OPT__(CXXUTILS_PP_ARG5_(__VA_ARGS__))
+#define CXXUTILS_PP_ARG5_(A, ...) CXXUTILS_PP_ARG4(__VA_ARGS__)
+
+
+#endif // not CXXUTILS_PPARGS_H

Control/CxxUtils/share/pputils_test.ref

+CxxUtils/pputils_test

Control/CxxUtils/test/pputils_test.cxx

+/*
+ * Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration.
+ */
+/**
+ * @file CxxUtils/test/pputils_test.cxx
+ * @author scott snyder <snyder@bnl.gov>
+ * @date May, 2024
+ * @brief Tests for pputils.
+ */
+
+
+#undef NDEBUG
+#include "CxxUtils/pputils.h"
+#include <iostream>
+#include <cassert>
+
+
+void check (int exp, int test=0)
+{
+  assert (exp == test);
+}
+
+
+int main()
+{
+  std::cout << "CxxUtils/pputils_test\n";
+  check (0 CXXUTILS_PP_FIRST());
+  check (1 CXXUTILS_PP_FIRST(1));
+  check (1 CXXUTILS_PP_ARG1(1, 2, 3));
+
+  check (0 CXXUTILS_PP_SECOND());
+  check (0 CXXUTILS_PP_SECOND(1));
+  check (2 CXXUTILS_PP_SECOND(1, 2));
+  check (2 CXXUTILS_PP_ARG2(1, 2, 3));
+
+  check (0 CXXUTILS_PP_THIRD());
+  check (0 CXXUTILS_PP_THIRD(1));
+  check (0 CXXUTILS_PP_THIRD(1, 2));
+  check (3 CXXUTILS_PP_THIRD(1, 2, 3));
+  check (3 CXXUTILS_PP_ARG3(1, 2, 3, 4));
+
+  check (0 CXXUTILS_PP_FOURTH());
+  check (0 CXXUTILS_PP_FOURTH(1));
+  check (0 CXXUTILS_PP_FOURTH(1, 2, 3));
+  check (4 CXXUTILS_PP_FOURTH(1, 2, 3, 4));
+  check (4 CXXUTILS_PP_ARG4(1, 2, 3, 4, 5));
+
+  check (0 CXXUTILS_PP_FIFTH());
+  check (0 CXXUTILS_PP_FIFTH(1));
+  check (0 CXXUTILS_PP_FIFTH(1, 2, 3, 4));
+  check (5 CXXUTILS_PP_FIFTH(1, 2, 3, 4, 5));
+  check (5 CXXUTILS_PP_ARG5(1, 2, 3, 4, 5, 6));
+
+  return 0;
+}