ensure compatibility for client_kill for g++ 4.8

Author: YiuRULE

includes/cpp_redis/future_client.hpp

@@ -310,7 +310,13 @@ class future_client {
 template <typename T, typename... Ts>
 future_client::future
 future_client::client_kill(const T& arg, const Ts&... args) {
-  return exec_cmd([=](const rcb_t& cb) -> rc& { return m_client.client_kill(arg, args..., cb); });
+
+  /** gcc 4.8 doesn't handle variadic template capture arguments (appears in 4.9), so std::bind should capture all arguments
+   *  because of the compiler
+   */
+  return exec_cmd(std::bind([this](const T& arg, const Ts&... args, const rcb_t& cb) {
+        return m_client.client_kill(arg, args..., cb);
+  }, arg, args...));
 }
 
 } //! cpp_redis