Add detail/pp_utilities.hpp

include/boost/describe/detail/pp_for_each.hpp

@@ -5,7 +5,7 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#define BOOST_DESCRIBE_PP_EXPAND(x) x
+#include <boost/describe/detail/pp_utilities.hpp>
 
 #define BOOST_DESCRIBE_PP_FOR_EACH_0(F, a)
 #define BOOST_DESCRIBE_PP_FOR_EACH_1(F, a, x) F(a, x)
@@ -61,10 +61,10 @@
 #define BOOST_DESCRIBE_PP_FOR_EACH_51(F, a, x, ...) BOOST_DESCRIBE_PP_EXPAND(F(a, x) BOOST_DESCRIBE_PP_FOR_EACH_50(F, a, __VA_ARGS__))
 #define BOOST_DESCRIBE_PP_FOR_EACH_52(F, a, x, ...) BOOST_DESCRIBE_PP_EXPAND(F(a, x) BOOST_DESCRIBE_PP_FOR_EACH_51(F, a, __VA_ARGS__))
 
-#define BOOST_DESCRIBE_PP_EXTRACT(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, V, ...) V
+#define BOOST_DESCRIBE_PP_FE_EXTRACT(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, V, ...) V
 
 #define BOOST_DESCRIBE_PP_FOR_EACH(F, ...) \
-    BOOST_DESCRIBE_PP_EXPAND(BOOST_DESCRIBE_PP_EXPAND(BOOST_DESCRIBE_PP_EXTRACT(__VA_ARGS__, \
+    BOOST_DESCRIBE_PP_EXPAND(BOOST_DESCRIBE_PP_EXPAND(BOOST_DESCRIBE_PP_FE_EXTRACT(__VA_ARGS__, \
     BOOST_DESCRIBE_PP_FOR_EACH_52, \
     BOOST_DESCRIBE_PP_FOR_EACH_51, \
     BOOST_DESCRIBE_PP_FOR_EACH_50, \

include/boost/describe/detail/pp_utilities.hpp

@@ -0,0 +1,48 @@
+#ifndef BOOST_DESCRIBE_DETAIL_PP_UTILITIES_HPP_INCLUDED
+#define BOOST_DESCRIBE_DETAIL_PP_UTILITIES_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#define BOOST_DESCRIBE_PP_EXPAND(x) x
+
+#define BOOST_DESCRIBE_PP_CAT(x, y) BOOST_DESCRIBE_PP_CAT_I(x, y)
+#define BOOST_DESCRIBE_PP_CAT_I(x, ...) x ## __VA_ARGS__
+
+#if defined(_MSC_VER) && !defined(__clang__)
+
+#define BOOST_DESCRIBE_PP_FIRST(x) BOOST_DESCRIBE_PP_FIRST_I((x))
+#define BOOST_DESCRIBE_PP_FIRST_I(x) BOOST_DESCRIBE_PP_FIRST_II x
+#define BOOST_DESCRIBE_PP_FIRST_II(x, ...) x
+
+#else
+
+#define BOOST_DESCRIBE_PP_FIRST(x) BOOST_DESCRIBE_PP_FIRST_I(x)
+#define BOOST_DESCRIBE_PP_FIRST_I(x, ...) x
+
+#endif
+
+#define BOOST_DESCRIBE_PP_IS_PAREN_I(x) BOOST_DESCRIBE_PP_CAT(BOOST_DESCRIBE_PP_IS_PAREN_I_, BOOST_DESCRIBE_PP_IS_PAREN_II x)
+#define BOOST_DESCRIBE_PP_IS_PAREN_II(...) 0
+#define BOOST_DESCRIBE_PP_IS_PAREN_I_0 1,
+#define BOOST_DESCRIBE_PP_IS_PAREN_I_BOOST_DESCRIBE_PP_IS_PAREN_II 0,
+
+#define BOOST_DESCRIBE_PP_IS_PAREN(x) BOOST_DESCRIBE_PP_FIRST(BOOST_DESCRIBE_PP_IS_PAREN_I(x))
+
+#define BOOST_DESCRIBE_PP_EMPTY
+
+#define BOOST_DESCRIBE_PP_IS_EMPTY(x) BOOST_DESCRIBE_PP_IS_EMPTY_I(BOOST_DESCRIBE_PP_IS_PAREN(x), BOOST_DESCRIBE_PP_IS_PAREN(x BOOST_DESCRIBE_PP_EMPTY ()))
+#define BOOST_DESCRIBE_PP_IS_EMPTY_I(x, y) BOOST_DESCRIBE_PP_IS_EMPTY_II(x, y)
+#define BOOST_DESCRIBE_PP_IS_EMPTY_II(x, y) BOOST_DESCRIBE_PP_IS_EMPTY_III(x, y)
+#define BOOST_DESCRIBE_PP_IS_EMPTY_III(x, y) BOOST_DESCRIBE_PP_IS_EMPTY_III_ ## x ## y
+#define BOOST_DESCRIBE_PP_IS_EMPTY_III_00 0
+#define BOOST_DESCRIBE_PP_IS_EMPTY_III_01 1
+#define BOOST_DESCRIBE_PP_IS_EMPTY_III_10 0
+#define BOOST_DESCRIBE_PP_IS_EMPTY_III_11 0
+
+#define BOOST_DESCRIBE_PP_CALL(F, a, x) BOOST_DESCRIBE_PP_CAT(BOOST_DESCRIBE_PP_CALL_I_, BOOST_DESCRIBE_PP_IS_EMPTY(x))(F, a, x)
+#define BOOST_DESCRIBE_PP_CALL_I_0(F, a, x) F(a, x)
+#define BOOST_DESCRIBE_PP_CALL_I_1(F, a, x)
+
+#endif // #ifndef BOOST_DESCRIBE_DETAIL_PP_UTILITIES_HPP_INCLUDED

test/Jamfile

@@ -15,6 +15,9 @@ project : requirements
 run quick.cpp ;
 
 run pp_for_each_test.cpp ;
+run pp_is_paren_test.cpp ;
+run pp_is_empty_test.cpp ;
+run pp_call_test.cpp ;
 
 run enumerators_test.cpp ;
 

test/pp_call_test.cpp

@@ -0,0 +1,43 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/pp_utilities.hpp>
+#include <boost/describe/detail/config.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX11)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++11 is not available")
+int main() {}
+
+#else
+
+#define S(x) S2(x)
+#define S2(x) S3(x)
+#define S3(x) #x
+
+#define F(a, x) (a, x)
+
+#if defined(_MSC_VER)
+# pragma warning(disable: 4003) // not enough arguments for macro invocation
+#endif
+
+char const * s1 = S(BOOST_DESCRIBE_PP_CALL(F, a, x));
+char const * s2 = "" S(BOOST_DESCRIBE_PP_CALL(F, a, ));
+char const * s3 = S(BOOST_DESCRIBE_PP_CALL(F, a, () x));
+char const * s4 = S(BOOST_DESCRIBE_PP_CALL(F, a, (b, c) x));
+
+int main()
+{
+    BOOST_TEST_CSTR_EQ( s1, "(a, x)" );
+    BOOST_TEST_CSTR_EQ( s2, "" );
+    BOOST_TEST_CSTR_EQ( s3, "(a, () x)" );
+    BOOST_TEST_CSTR_EQ( s4, "(a, (b, c) x)" );
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX11)

test/pp_is_empty_test.cpp

@@ -0,0 +1,40 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/pp_utilities.hpp>
+#include <boost/describe/detail/config.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX11)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++11 is not available")
+int main() {}
+
+#else
+
+#define S(x) S2(x)
+#define S2(x) #x
+
+#if defined(_MSC_VER)
+# pragma warning(disable: 4003) // not enough arguments for macro invocation
+#endif
+
+char const * s1 = S(BOOST_DESCRIBE_PP_IS_EMPTY());
+char const * s2 = S(BOOST_DESCRIBE_PP_IS_EMPTY(x));
+char const * s3 = S(BOOST_DESCRIBE_PP_IS_EMPTY(() x));
+char const * s4 = S(BOOST_DESCRIBE_PP_IS_EMPTY((a, b) x));
+
+int main()
+{
+    BOOST_TEST_CSTR_EQ( s1, "1" );
+    BOOST_TEST_CSTR_EQ( s2, "0" );
+    BOOST_TEST_CSTR_EQ( s3, "0" );
+    BOOST_TEST_CSTR_EQ( s4, "0" );
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX11)

test/pp_is_paren_test.cpp

@@ -0,0 +1,41 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/pp_utilities.hpp>
+#include <boost/describe/detail/config.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX11)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++11 is not available")
+int main() {}
+
+#else
+
+#define S(x) S2(x)
+#define S2(x) S3(x)
+#define S3(x) #x
+
+#if defined(_MSC_VER)
+# pragma warning(disable: 4003) // not enough arguments for macro invocation
+#endif
+
+char const * s1 = S(BOOST_DESCRIBE_PP_IS_PAREN());
+char const * s2 = S(BOOST_DESCRIBE_PP_IS_PAREN(x));
+char const * s3 = S(BOOST_DESCRIBE_PP_IS_PAREN(() x));
+char const * s4 = S(BOOST_DESCRIBE_PP_IS_PAREN((a, b) x));
+
+int main()
+{
+    BOOST_TEST_CSTR_EQ( s1, "0" );
+    BOOST_TEST_CSTR_EQ( s2, "0" );
+    BOOST_TEST_CSTR_EQ( s3, "1" );
+    BOOST_TEST_CSTR_EQ( s4, "1" );
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX11)