$OpenBSD: patch-gr-qtgui_lib_const_sink_c_impl_cc,v 1.1 2021/03/18 19:51:44 rsadowski Exp $

Build with newer Boost. From Fedora.

Index: gr-qtgui/lib/const_sink_c_impl.cc
--- gr-qtgui/lib/const_sink_c_impl.cc.orig
+++ gr-qtgui/lib/const_sink_c_impl.cc
@@ -35,6 +35,8 @@
 namespace gr {
 namespace qtgui {
 
+using namespace boost::placeholders;
+
 const_sink_c::sptr
 const_sink_c::make(int size, const std::string& name, int nconnections, QWidget* parent)
 {
