Add new macro BOOST_PARSER_GCC that is defined in config.hpp only for real

(non-Clang-emulated) GCC builds; replace relevant uses of the __GNUC__ macro
with BOOST_PARSER_GCC.

See discussion in PR #211.

Author: tzlaine

include/boost/parser/config.hpp

@@ -73,6 +73,12 @@
 
 #endif
 
+// Follows logic in boost/config/detail/select_compiler_config.hpp.
+#if defined(__clang__) && !defined(__ibmxl__) && !defined(__CODEGEARC__)
+#elif defined(__GNUC__) && !defined(__ibmxl__)
+#define BOOST_PARSER_GCC
+#endif
+
 #if defined(__cpp_lib_constexpr_algorithms)
 #    define BOOST_PARSER_ALGO_CONSTEXPR constexpr
 #else

include/boost/parser/detail/stl_interfaces/view_adaptor.hpp

@@ -24,8 +24,9 @@
 #define BOOST_PARSER_USE_CPP23_STD_RANGE_ADAPTOR_CLOSURE 0
 #endif
 
-#if !BOOST_PARSER_USE_CPP23_STD_RANGE_ADAPTOR_CLOSURE &&               \
-    BOOST_PARSER_DETAIL_STL_INTERFACES_USE_CONCEPTS && defined(__GNUC__) && 12 <= __GNUC__
+#if !BOOST_PARSER_USE_CPP23_STD_RANGE_ADAPTOR_CLOSURE &&                       \
+    BOOST_PARSER_DETAIL_STL_INTERFACES_USE_CONCEPTS &&                         \
+    defined(BOOST_PARSER_GCC) && 12 <= __GNUC__
 #define BOOST_PARSER_USE_LIBSTDCPP_GCC12_RANGE_ADAPTOR_CLOSURE 1
 #else
 #define BOOST_PARSER_USE_LIBSTDCPP_GCC12_RANGE_ADAPTOR_CLOSURE 0

include/boost/parser/detail/text/detail/all_t.hpp

@@ -42,7 +42,8 @@ namespace boost::parser::detail::text::detail {
     template<typename R>
     constexpr bool view =
 #if BOOST_PARSER_DETAIL_TEXT_USE_CONCEPTS ||                                   \
-    (defined(__cpp_lib_concepts) && (!defined(__GNUC__) || 12 <= __GNUC__))
+    (defined(__cpp_lib_concepts) &&                                            \
+     (!defined(BOOST_PARSER_GCC) || 12 <= __GNUC__))
         std::ranges::view<R>
 #else
         range_<R> && !container_<R> &&

include/boost/parser/transform_replace.hpp

@@ -4,7 +4,8 @@
 #include <boost/parser/replace.hpp>
 
 #if (!defined(_MSC_VER) || BOOST_PARSER_USE_CONCEPTS) &&                       \
-    (!defined(__GNUC__) || 12 <= __GNUC__ || !BOOST_PARSER_USE_CONCEPTS)
+    (!defined(BOOST_PARSER_GCC) || 12 <= __GNUC__ ||                           \
+     !BOOST_PARSER_USE_CONCEPTS)
 
 
 namespace boost::parser {