add boost on mac

macx64/include/boost/chrono/io/utility/to_string.hpp

@@ -0,0 +1,50 @@
+//  boost/chrono/utility/to_string.hpp
+//
+//  Copyright 2011 Vicente J. Botet Escriba
+//  Use, modification and distribution are subject to 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_CHRONO_UTILITY_TO_STRING_HPP
+#define BOOST_CHRONO_UTILITY_TO_STRING_HPP
+
+#include <boost/chrono/config.hpp>
+#include <string>
+#include <sstream>
+
+namespace boost
+{
+  namespace chrono
+  {
+    template <typename CharT, typename T>
+    std::basic_string<CharT> to_basic_string(T const&v) {
+      std::basic_stringstream<CharT> sstr;
+      sstr << v;
+      return sstr.str();
+    }
+
+    template <typename T>
+    std::string to_string(T const&v) {
+      return to_basic_string<char>(v);
+    }
+#ifndef BOOST_NO_STD_WSTRING
+    template <typename T>
+    std::wstring to_wstring(T const&v) {
+      return to_basic_string<wchar_t>(v);
+    }
+#endif
+#if BOOST_CHRONO_HAS_UNICODE_SUPPORT
+    template <typename T>
+    std::basic_string<char16_t> to_u16string(T const&v) {
+      return to_basic_string<char16_t>(v);
+    }
+    template <typename T>
+    std::basic_string<char32_t> to_u32string(T const&v) {
+      return to_basic_string<char32_t>(v);
+    }
+#endif
+  } // chrono
+
+} // boost
+
+#endif  // header