Use gcc7 for better lcov

Author: cinemast

.circleci/config.yml

@@ -10,7 +10,7 @@ jobs:
       - checkout
       - run:
           name: Installing GCC and CMake
-          command: 'apt-get update && apt-get install -y gcc g++ cmake lcov curl'
+          command: 'apt-get update && apt-get install -y gcc-7 cmake lcov curl'
       - run:
           name: Build
           command: cmake -DCOMPILE_TESTS=ON -DCOMPILE_EXAMPLES=ON -DCODE_COVERAGE=ON . && cmake --build .

include/jsonrpccxx/typemapper.hpp

@@ -52,10 +52,8 @@ namespace jsonrpccxx {
       return "array";
     case json::value_t::string:
       return "string";
-    case json::value_t::null:
-      return "null";
     default:
-      return "unknown type";
+      return "null";
     }
   }