Fix builds with older gcc versions (at least 5.4.0)

CMakeLists.txt

@@ -29,6 +29,10 @@
 cmake_minimum_required(VERSION 3.1.0)
 project(monero-lws)
 
+enable_language(CXX)
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
 set(MONERO_LIBRARIES
   daemon_messages
   serialization

src/rest_server.cpp

@@ -141,7 +141,7 @@ namespace lws
         if (!user)
           return user.error();
 
-        response resp{.rates = {common_error::kInvalidArgument}};
+        response resp{};
 
         auto outputs = user->second.get_outputs(user->first.id);
         if (!outputs)

src/rpc/json.h

@@ -43,7 +43,7 @@ namespace rpc
     unsigned id;
     const char* method; //!< Must be in static memory
   };
-  const char json_request_base::jsonrpc[];
+  constexpr const char json_request_base::jsonrpc[];
 
   //! \tparam W implements the WRITE concept \tparam M implements the METHOD concept
   template<typename W, typename M>

src/rpc/light_wallet.h

@@ -76,7 +76,19 @@ namespace rpc
 
   struct get_address_info_response
   {
-    get_address_info_response() = delete;
+    get_address_info_response() noexcept
+      : locked_funds(safe_uint64(0)),
+        total_received(safe_uint64(0)),
+        total_sent(safe_uint64(0)),
+        scanned_height(0),
+        scanned_block_height(0),
+        start_height(0),
+        transaction_height(0),
+        blockchain_height(0),
+        spent_outputs(),
+        rates(common_error::kInvalidArgument)
+    {}
+
     safe_uint64 locked_funds;
     safe_uint64 total_received;
     safe_uint64 total_sent;