rethinkdb: boost 1.56 compatibility

Formula/rethinkdb.rb

@@ -19,6 +19,10 @@ class Rethinkdb < Formula
     cause "RethinkDB uses C++0x"
   end
 
+  # boost 1.56 compatibility
+  # https://github.com/rethinkdb/rethinkdb/issues/3044#issuecomment-55478774
+  patch :DATA
+
   def install
     args = ["--prefix=#{prefix}"]
 
@@ -29,6 +33,10 @@ class Rethinkdb < Formula
     # but brew's protobuf is sometimes linked against libstdc++
     args += ["--fetch", "protobuf"]
 
+    # support gcc with boost 1.56
+    # https://github.com/rethinkdb/rethinkdb/issues/3044#issuecomment-55471981
+    args << "CXXFLAGS=-DBOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES"
+
     system "./configure", *args
     system "make"
     system "make", "install-osx"
@@ -64,3 +72,17 @@ class Rethinkdb < Formula
     EOS
   end
 end
+__END__
+diff --git a/src/clustering/reactor/reactor_be_primary.cc b/src/clustering/reactor/reactor_be_primary.cc
+index 3f583fc..945f78b 100644
+--- a/src/clustering/reactor/reactor_be_primary.cc
++++ b/src/clustering/reactor/reactor_be_primary.cc
+@@ -290,7 +290,7 @@ void do_backfill(
+
+ bool check_that_we_see_our_broadcaster(const boost::optional<boost::optional<broadcaster_business_card_t> > &maybe_a_
+     guarantee(maybe_a_business_card, "Not connected to ourselves\n");
+-    return maybe_a_business_card.get();
++    return static_cast<bool>(maybe_a_business_card.get());
+ }
+
+ bool reactor_t::attempt_backfill_from_peers(directory_entry_t *directory_entry,