Use implicit nullables.

Author: evoskuil

src/rest/rest.cpp

@@ -226,8 +226,9 @@ code path_to_request(request_t& out, const std::string& path) NOEXCEPT
             const auto hash = to_hash(segments[segment++]);
             if (!hash) return error::invalid_hash;
 
+            // nullables can be implicit.
+            ////params["height"] = null_t{};
             params["hash"] = hash;
-            params["height"] = null_t{};
         }
         else if (by == "height")
         {
@@ -238,7 +239,8 @@ code path_to_request(request_t& out, const std::string& path) NOEXCEPT
             if (!to_number(height, segments[segment++]))
                 return error::invalid_number;
 
-            params["hash"] = null_t{};
+            // nullables can be implicit.
+            ////params["hash"] = null_t{};
             params["height"] = height;
         }
         else

test/rest/rest.cpp

@@ -84,7 +84,7 @@ BOOST_AUTO_TEST_CASE(path_to_request__block_height_valid___expected_request)
     BOOST_REQUIRE(std::holds_alternative<object_t>(params));
 
     const auto& object = std::get<object_t>(request.params.value());
-    BOOST_REQUIRE_EQUAL(object.size(), 3u);
+    BOOST_REQUIRE_EQUAL(object.size(), 2u);
 
     const auto version = std::get<uint8_t>(object.at("version").value());
     BOOST_REQUIRE_EQUAL(version, 42u);