1 files changed, 40 insertions, 0 deletions
diff --git a/src/boost/libs/histogram/test/std_ostream.hpp b/src/boost/libs/histogram/test/std_ostream.hpp
new file mode 100644
index 000000000..8a181d98d
--- /dev/null
+++ b/src/boost/libs/histogram/test/std_ostream.hpp
@@ -0,0 +1,40 @@
+// Copyright 2018-2019 Hans Dembinski
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_HISTOGRAM_TEST_STD_OSTREAM_HPP
+#define BOOST_HISTOGRAM_TEST_STD_OSTREAM_HPP
+
+#include <boost/mp11/tuple.hpp>
+#include <ostream>
+#include <utility>
+#include <vector>
+
+namespace std {
+// never add to std, we only do it here to get ADL working :(
+template <class T>
+ostream& operator<<(ostream& os, const vector<T>& v) {
+  os << "[ ";
+  for (const auto& x : v) os << x << " ";
+  os << "]";
+  return os;
+}
+
+template <class... Ts>
+ostream& operator<<(ostream& os, const std::tuple<Ts...>& t) {
+  os << "[ ";
+  ::boost::mp11::tuple_for_each(t, [&os](const auto& x) { os << x << " "; });
+  os << "]";
+  return os;
+}
+
+template <class T, class U>
+ostream& operator<<(ostream& os, const std::pair<T, U>& t) {
+  os << "[ " << t.first << " " << t.second << " ]";
+  return os;
+}
+} // namespace std
+
+#endif