Use variants to support objects as semantic values.

[bison.git] / data / c++.m4

diff --git a/data/c++.m4 b/data/c++.m4
index a896b778bd53a0857ad43418b105baf0512847b9..ba17dff1d97175ddb85a76a89a9af628988f30d7 100644 (file)
--- a/data/c++.m4
+++ b/data/c++.m4
@@ -97,6 +97,11 @@ m4_map_sep([     b4_token_enum], [,
 ## Semantic Values.  ##
 ## ----------------- ##
 
+# b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
+# ----------------------------------------------
+m4_define([b4_variant_if],
+[b4_percent_define_ifdef([[variant]], [$1], [$2])])
+
 
 # b4_lhs_value([TYPE])
 # --------------------