From 6baf14372d7126285bf8b661731b69c400d2106c Mon Sep 17 00:00:00 2001
 From: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
 Date: Fri, 31 Aug 2018 10:20:31 -0700
 Subject: [PATCH] lightstep-tracer-cpp: Fix build issues with gcc 7.3
 
 In file included from lightstep/impl.h:11:0,
                  from span.cc:1:
 ./lightstep/options.h:42:8: error: 'function' in namespace 'std' does not name a template type
    std::function<uint64_t()> guid_generator;
         ^~~~~~~~
 
 Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
 ---
 diff -Naurp lightstep-tracer-cpp-0.19-orig/src/c++11/lightstep/impl.h lightstep-tracer-cpp-0.19-modified/src/c++11/lightstep/impl.h
 --- lightstep-tracer-cpp-0.19-orig/src/c++11/lightstep/impl.h	2016-11-30 14:51:38.000000000 -0800
 +++ lightstep-tracer-cpp-0.19-modified/src/c++11/lightstep/impl.h	2018-08-31 10:21:13.049573107 -0700
 @@ -6,6 +6,7 @@
  #include <memory>
  #include <mutex>
  #include <random>
 +#include <functional>
  
  #include "lightstep/collector.pb.h"
  #include "lightstep/options.h"