http::request::raw should be const

websocketpp/http/impl/request.hpp

@@ -131,7 +131,7 @@ inline size_t request::consume(const char *buf, size_t len) {
     }
 }
 
-inline std::string request::raw() {
+inline std::string request::raw() const {
     // TODO: validation. Make sure all required fields have been set?
     std::stringstream ret;
 

websocketpp/http/request.hpp

@@ -85,7 +85,7 @@ public:
     }
 
     /// Returns the full raw request
-    std::string raw();
+    std::string raw() const;
 
     /// Set the HTTP method. Must be a valid HTTP token
     void set_method(const std::string& method);