New buffers() replaces to_string() (API Change):

A new function, buffers(), returns an implementation defined object
which wraps a ConstBufferSequence and supports formatting to a
std::ostream.

The function to_string is removed, as the new implementation allows
conversion to string using boost::lexical_cast on the return value
of the call to buffers(). Streaming to an output stream is more
efficient: no dynamic allocations are performed.

Example:

    streambuf sb;
    std::cout << buffers(sb.data()) << std::endl;

test/websocket/stream.cpp

@@ -11,8 +11,8 @@
 #include "websocket_async_echo_server.hpp"
 #include "websocket_sync_echo_server.hpp"
 
+#include <beast/core/ostream.hpp>
 #include <beast/core/streambuf.hpp>
-#include <beast/core/to_string.hpp>
 #include <beast/test/fail_stream.hpp>
 #include <beast/test/string_istream.hpp>
 #include <beast/test/string_iostream.hpp>
@@ -38,6 +38,15 @@ public:
     using address_type = boost::asio::ip::address;
     using socket_type = boost::asio::ip::tcp::socket;
 
+    template<class ConstBufferSequence>
+    static
+    std::string
+    to_string(ConstBufferSequence const& bs)
+    {
+        return boost::lexical_cast<
+            std::string>(buffers(bs));
+    }
+
     struct con
     {
         stream<socket_type> ws;
@@ -1169,7 +1178,8 @@ public:
         );
     }
 
-    void testMask(endpoint_type const& ep,
+    void
+    testMask(endpoint_type const& ep,
         yield_context do_yield)
     {
         {