Borland workarounds

[SVN r21893]

include/boost/iterator/detail/config_def.hpp

@@ -122,4 +122,16 @@
 #  define BOOST_ARG_DEPENDENT_TYPENAME
 # endif
 
-// no include guard multiple inclusion intended
+# if BOOST_WORKAROUND(__GNUC__, == 2) && BOOST_WORKAROUND(__GNUC_MINOR__, BOOST_TESTED_AT(95)) \
+    || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
+
+// GCC-2.95 eagerly instantiates templated constructors and conversion
+// operators in convertibility checks, causing premature errors.
+//
+// Borland's problems are harder to diagnose due to lack of an
+// instantiation stack backtrace.  They may be due in part to the fact
+// that it drops cv-qualification willy-nilly in templates.
+#  define BOOST_NO_ONE_WAY_ITERATOR_INTEROP
+# endif 
+
+// no include guard; multiple inclusion intended

include/boost/iterator/detail/config_undef.hpp

@@ -18,6 +18,7 @@
 #undef BOOST_NO_STRICT_ITERATOR_INTEROPERABILITY
 #undef BOOST_ARG_DEPENDENT_TYPENAME
 #undef BOOST_NO_LVALUE_RETURN_DETECTION
+#undef BOOST_NO_ONE_WAY_ITERATOR_INTEROP
 
 #ifdef BOOST_ITERATOR_CONFIG_DEF
 # undef BOOST_ITERATOR_CONFIG_DEF

include/boost/iterator/iterator_facade.hpp

@@ -228,7 +228,7 @@ namespace boost
         template <class I1, class I2>
         struct apply
           :
-# if BOOST_WORKAROUND(__GNUC__, == 2) && BOOST_WORKAROUND(__GNUC_MINOR__, BOOST_TESTED_AT(95))
+# ifdef BOOST_NO_ONE_WAY_ITERATOR_INTEROP
           iterator_difference<I1>
 # elif BOOST_WORKAROUND(BOOST_MSVC, == 1200)
           mpl::if_<
@@ -575,9 +575,7 @@ namespace boost
   // ----------------
   //
 
-# if BOOST_WORKAROUND(__GNUC__, == 2) && BOOST_WORKAROUND(__GNUC_MINOR__, BOOST_TESTED_AT(95))
-// GCC-2.95 eagerly instantiates templated constructors and conversion
-// operators in convertibility checks, causing premature errors.
+# ifdef BOOST_NO_ONE_WAY_ITERATOR_INTEROP
 #  define BOOST_ITERATOR_CONVERTIBLE(a,b) mpl::true_()
 # else
 #  define BOOST_ITERATOR_CONVERTIBLE(a,b) is_convertible<a,b>()