diff --git a/libs/boost/boost/mpl/apply.hpp b/libs/boost/boost/mpl/apply.hpp
index 345344e..d5ed8d7 100644
--- a/libs/boost/boost/mpl/apply.hpp
+++ b/libs/boost/boost/mpl/apply.hpp
@@ -135,7 +135,7 @@ struct apply
 
 ///// iteration, depth == 1
 
-#elif BOOST_PP_ITERATION_DEPTH() == 1
+#elif BOOST_PP_ITERATION_DEPTH == 1
 
 #   define i_ BOOST_PP_FRAME_ITERATION(1)
 
diff --git a/libs/boost/boost/mpl/apply_wrap.hpp b/libs/boost/boost/mpl/apply_wrap.hpp
index 355a8f1..d122127 100644
--- a/libs/boost/boost/mpl/apply_wrap.hpp
+++ b/libs/boost/boost/mpl/apply_wrap.hpp
@@ -78,7 +78,7 @@ namespace boost { namespace mpl {
 
 ///// iteration, depth == 1
 
-#elif BOOST_PP_ITERATION_DEPTH() == 1
+#elif BOOST_PP_ITERATION_DEPTH == 1
 
 #   define i_ BOOST_PP_FRAME_ITERATION(1)
 
@@ -170,7 +170,7 @@ struct BOOST_PP_CAT(apply_wrap,i_)<AUX778076_APPLY_WRAP_SPEC_PARAMS(i_, int)>
 
 ///// iteration, depth == 2
 
-#elif BOOST_PP_ITERATION_DEPTH() == 2
+#elif BOOST_PP_ITERATION_DEPTH == 2
 
 #   define j_ BOOST_PP_FRAME_ITERATION(2)
 
diff --git a/libs/boost/boost/mpl/aux_/full_lambda.hpp b/libs/boost/boost/mpl/aux_/full_lambda.hpp
index 745e6cd..f797c7e 100644
--- a/libs/boost/boost/mpl/aux_/full_lambda.hpp
+++ b/libs/boost/boost/mpl/aux_/full_lambda.hpp
@@ -227,7 +227,7 @@ BOOST_MPL_AUX_NA_SPEC2(2, 3, lambda)
 
 ///// iteration, depth == 1
 
-#elif BOOST_PP_ITERATION_DEPTH() == 1
+#elif BOOST_PP_ITERATION_DEPTH == 1
 #define i_ BOOST_PP_FRAME_ITERATION(1)
 
 #if i_ > 0
diff --git a/libs/boost/boost/mpl/aux_/numeric_op.hpp b/libs/boost/boost/mpl/aux_/numeric_op.hpp
index ff76a09..de74f63 100644
--- a/libs/boost/boost/mpl/aux_/numeric_op.hpp
+++ b/libs/boost/boost/mpl/aux_/numeric_op.hpp
@@ -287,7 +287,7 @@ BOOST_MPL_AUX_NA_SPEC2(2, AUX778076_OP_ARITY, AUX778076_OP_NAME)
 
 ///// iteration, depth == 1
 
-#elif BOOST_PP_ITERATION_DEPTH() == 1
+#elif BOOST_PP_ITERATION_DEPTH == 1
 
 #   define i_ BOOST_PP_FRAME_ITERATION(1)
 
diff --git a/libs/boost/boost/mpl/bind.hpp b/libs/boost/boost/mpl/bind.hpp
index 6e396b6..e364c0f 100644
--- a/libs/boost/boost/mpl/bind.hpp
+++ b/libs/boost/boost/mpl/bind.hpp
@@ -361,7 +361,7 @@ BOOST_MPL_AUX_TEMPLATE_ARITY_SPEC(
 
 ///// iteration, depth == 1
 
-#elif BOOST_PP_ITERATION_DEPTH() == 1
+#elif BOOST_PP_ITERATION_DEPTH == 1
 
 #   define i_ BOOST_PP_FRAME_ITERATION(1)
 
@@ -528,7 +528,7 @@ struct bind_chooser<i_>
 
 ///// iteration, depth == 2
 
-#elif BOOST_PP_ITERATION_DEPTH() == 2
+#elif BOOST_PP_ITERATION_DEPTH == 2
 
 #   define j_ BOOST_PP_FRAME_ITERATION(2)
 #   if !defined(BOOST_MPL_CFG_NO_UNNAMED_PLACEHOLDER_SUPPORT)