testing some classifiers permutations

include/boost/contract/ext_/preprocessor/keyword/utility/remove.hpp

@@ -8,12 +8,13 @@
 
 // NOTE: All these levels of indirection (instead of doing the PP_CAT directly)
 // are necessary to ensure proper macro expansion on MSVC which would otherwise
-// get confused sometimes.
-
-#define BOOST_CONTRACT_EXT_PP_KEYWORD_UTILITY_REMOVE_EXPAND1_(x) x
+// get confused sometimes. Also, use its own implementation of EXPAND_ONCE to
+// avoid reentrancy issues. 
+#define BOOST_CONTRACT_EXT_PP_KEYWORD_UTILITY_REMOVE_EXPAND_ONCE_(x) x
 
 #define BOOST_CONTRACT_EXT_PP_KEYWORD_UTILITY_REMOVE_CAT_(a, b) \
-    BOOST_CONTRACT_EXT_PP_KEYWORD_UTILITY_REMOVE_EXPAND1_(BOOST_PP_CAT(a, b))
+    BOOST_CONTRACT_EXT_PP_KEYWORD_UTILITY_REMOVE_EXPAND_ONCE_( \
+            BOOST_PP_CAT(a, b))
 
 /* PUBLIC */
 

include/boost/contract/ext_/preprocessor/traits/adt.hpp

@@ -46,13 +46,13 @@
 // NOTE: Using `BOOST_PP_TUPLE_ELEM(2, 0, sign_traits)` instead of this
 // confuses MSVC macro expansion sometimes (OK on GCC, CLang, Wave, etc.).
 #define BOOST_CONTRACT_EXT_PP_SIGN_TRAITS_FIRST(sign_traits) \
-    BOOST_CONTRACT_EXT_PP_EXPAND1( \
+    BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
             BOOST_CONTRACT_EXT_PP_SIGN_TRAITS_FIRST_ sign_traits)
 
 // NOTE: Using `BOOST_PP_TUPLE_ELEM(2, 1, sign_traits)` instead of this
 // confuses MSVC macro expansion sometimes (OK on GCC, CLang, Wave, etc.).
 #define BOOST_CONTRACT_EXT_PP_SIGN_TRAITS_SECOND(sign_traits) \
-    BOOST_CONTRACT_EXT_PP_EXPAND1( \
+    BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
             BOOST_CONTRACT_EXT_PP_SIGN_TRAITS_SECOND_ sign_traits)
 
 #endif // #include guard

include/boost/contract/ext_/preprocessor/traits/func/classifiers.hpp

@@ -11,6 +11,7 @@
 #include <boost/contract/ext_/preprocessor/keyword/friend.hpp>
 #include <boost/contract/ext_/preprocessor/keyword/inline.hpp>
 #include <boost/contract/ext_/preprocessor/utility/expand.hpp>
+#include <boost/contract/ext_/preprocessor/utility/idem.hpp>
 #include <boost/preprocessor/tuple/elem.hpp>
 #include <boost/preprocessor/control/while.hpp>
 #include <boost/preprocessor/control/iif.hpp>
@@ -32,7 +33,7 @@
 
 #define BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_CLASSIFIERS_OP_ARGS_(continue_, \
         sign, inline_, static_, extern_, explicit_, virtual_, friend_) \
-    BOOST_CONTRACT_EXT_PP_EXPAND1( \
+    BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
         BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_CLASSIFIERS_SIGN_ \
         BOOST_PP_IIF(BOOST_PP_BITAND(BOOST_PP_COMPL(inline_), \
                 BOOST_CONTRACT_EXT_PP_KEYWORD_IS_INLINE_FRONT(sign)), \
@@ -59,14 +60,14 @@
             (1, BOOST_CONTRACT_EXT_PP_KEYWORD_FRIEND_REMOVE_FRONT, sign, \
             inline_, static_, extern_, explicit_, virtual_, 1) \
         , \
-            (0, BOOST_CONTRACT_EXT_PP_EXPAND1, sign, \
+            (0, BOOST_CONTRACT_EXT_PP_IDEM, sign, \
             inline_, static_, extern_, explicit_, virtual_, friend_) \
         )))))) \
     )
         
 #define BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_CLASSIFIERS_OP_( \
         d, continue_sign_inline_static_extern_explicit_virtual_friend) \
-    BOOST_CONTRACT_EXT_PP_EXPAND1( \
+    BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
         BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_CLASSIFIERS_OP_ARGS_ \
         continue_sign_inline_static_extern_explicit_virtual_friend \
     )

include/boost/contract/ext_/preprocessor/traits/func/export.hpp

@@ -39,10 +39,10 @@
 
 #define BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_EXPORT_PARSE(sign_traits) \
     ( \
-        BOOST_CONTRACT_EXT_PP_EXPAND1( \
+        BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
                 BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_EXPORT_SIGN_ sign_traits) \
     , \
-        BOOST_CONTRACT_EXT_PP_EXPAND1( \
+        BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
                 BOOST_CONTRACT_EXT_PP_FUNC_TRAITS_EXPORT_TRAIT_ sign_traits) \
     )
 

include/boost/contract/ext_/preprocessor/traits/tparam/kind.hpp

@@ -65,10 +65,10 @@
     
 #define BOOST_CONTRACT_EXT_PP_TPARAM_TRAITS_KIND_PARSE(sign_traits) \
     ( \
-        BOOST_CONTRACT_EXT_PP_EXPAND1( \
+        BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
                 BOOST_CONTRACT_EXT_PP_TPARAM_TRAITS_KIND_SIGN_ sign_traits) \
     , \
-        BOOST_CONTRACT_EXT_PP_EXPAND1( \
+        BOOST_CONTRACT_EXT_PP_EXPAND_ONCE( \
                 BOOST_CONTRACT_EXT_PP_TPARAM_TRAITS_KIND_TRAIT_ sign_traits) \
     )
 

include/boost/contract/ext_/preprocessor/utility/expand.hpp

@@ -5,14 +5,19 @@
 /* PUBLIC */
 
 // Expand its argument once, `BOOST_PP_EXPAND` expands it twice instead:
-//  EXPAND1(x) --> x                   (x expanded once)
-//  EXPAND(x)  --> EXPAND_(x) --> x    (x expanded twice)
-// NOTE: This macro is sometimes useful to enforce proper macro expansion on
+//  EXPAND_ONCE(x)  --> x                   (x expanded once)
+//  EXPAND(x)       --> EXPAND_(x) --> x    (x expanded twice)
+// This macro is sometimes useful to enforce proper macro expansion at least on
 // MSVC (on better preprocessors like GCC, CLang, and Wave this macro is not
-// necessary instead). For example, `EXPAND1(macro args) ...` where `args` is
-// `(a, b EMPTY)` expands to `macro(a, b EMPTY) ...`. Otherwise, MSVC would
+// necessary instead). For example, `EXPAND_ONCE(macro args) ...` where `args`
+// is `(a, b EMPTY)` expands to `macro(a, b EMPTY) ...`. Otherwise, MSVC would
 // sometimes confuse `...` as arguments for `EMPTY`, etc.
-#define BOOST_CONTRACT_EXT_PP_EXPAND1(tokens) tokens
+// NOTE:
+//  *   In theory this macro is equivalent to `IDEM(tokens)` but these are
+//      logically different, plus not using both macros confuses MSVC sometimes.
+//  *   In theory this macro is also equivalent to `BOOST_PP_REM(1) (tokens)`
+//      but again that confuses MSVC sometimes.
+#define BOOST_CONTRACT_EXT_PP_EXPAND_ONCE(tokens) tokens
 
 #endif // #include gaurd
 

include/boost/contract/ext_/preprocessor/utility/idem.hpp

@@ -0,0 +1,16 @@
+
+#ifndef BOOST_CONTRACT_EXT_PP_IDEM_HPP_
+#define BOOST_CONTRACT_EXT_PP_IDEM_HPP_
+
+/* PUBLIC */
+
+// NOTE:
+//  *   In theory this macro is equivalent to `EXPAND_ONCE(tokens)` but these
+//      are logically different plus not using both macros confuses MSVC
+//      sometimes.
+//  *   In theory this macro is also equivalent to `BOOST_PP_REM(1) (tokens)`
+//      but again that confuses MSVC sometimes.
+#define BOOST_CONTRACT_EXT_PP_IDEM(tokens) tokens
+
+#endif // #include guard
+