[all] Replace Result<T> with optional<T> plus out Error parameter

2 files changed, 22 insertions, 16 deletions

diff --git a/platform/qt/src/qmapboxgl.cpp b/platform/qt/src/qmapboxgl.cpp
index b1c0a11ee1..3d5da10c36 100644
--- a/platform/qt/src/qmapboxgl.cpp
+++ b/platform/qt/src/qmapboxgl.cpp
@@ -1250,9 +1250,10 @@ void QMapboxGL::addSource(const QString &id, const QVariantMap &params)
     using namespace mbgl::style;
     using namespace mbgl::style::conversion;
 
-    Result<std::unique_ptr<Source>> source = convert<std::unique_ptr<Source>>(QVariant(params), id.toStdString());
+    Error error;
+    mbgl::optional<std::unique_ptr<Source>> source = convert<std::unique_ptr<Source>>(QVariant(params), error, id.toStdString());
     if (!source) {
-        qWarning() << "Unable to add source:" << source.error().message.c_str();
+        qWarning() << "Unable to add source:" << error.message.c_str();
         return;
     }
 
@@ -1291,7 +1292,8 @@ void QMapboxGL::updateSource(const QString &id, const QVariantMap &params)
     }
 
     if (params.contains("data")) {
-        auto result = convertGeoJSON(params["data"]);
+        Error error;
+        auto result = convertGeoJSON(params["data"], error);
         if (result) {
             sourceGeoJSON->setGeoJSON(*result);
         }
@@ -1362,9 +1364,10 @@ void QMapboxGL::addLayer(const QVariantMap &params)
     using namespace mbgl::style;
     using namespace mbgl::style::conversion;
 
-    Result<std::unique_ptr<Layer>> layer = convert<std::unique_ptr<Layer>>(QVariant(params));
+    Error error;
+    mbgl::optional<std::unique_ptr<Layer>> layer = convert<std::unique_ptr<Layer>>(QVariant(params), error);
     if (!layer) {
-        qWarning() << "Unable to add layer:" << layer.error().message.c_str();
+        qWarning() << "Unable to add layer:" << error.message.c_str();
         return;
     }
 
@@ -1445,9 +1448,10 @@ void QMapboxGL::setFilter(const QString& layer, const QVariant& filter)
 
     Filter filter_;
 
-    Result<Filter> converted = convert<Filter>(filter);
+    Error error;
+    mbgl::optional<Filter> converted = convert<Filter>(filter, error);
     if (!converted) {
-        qWarning() << "Error parsing filter:" << converted.error().message.c_str();
+        qWarning() << "Error parsing filter:" << error.message.c_str();
         return;
     }
     filter_ = std::move(*converted);
diff --git a/platform/qt/src/qt_geojson.hpp b/platform/qt/src/qt_geojson.hpp
index 038b051941..7c50c663dd 100644
--- a/platform/qt/src/qt_geojson.hpp
+++ b/platform/qt/src/qt_geojson.hpp
@@ -180,20 +180,21 @@ namespace style {
 namespace conversion {
 
 template <>
-Result<GeoJSON> convertGeoJSON(const QMapbox::Feature& feature) {
-    return Result<GeoJSON> { GeoJSON { asMapboxGLFeature(feature) } };
+optional<GeoJSON> convertGeoJSON(const QMapbox::Feature& feature, Error&) {
+    return GeoJSON { asMapboxGLFeature(feature) };
 }
 
 template <>
-Result<GeoJSON> convertGeoJSON(const QVariant& value) {
+optional<GeoJSON> convertGeoJSON(const QVariant& value, Error& error) {
 #if QT_VERSION >= 0x050000
     if (value.typeName() == QStringLiteral("QMapbox::Feature")) {
 #else
     if (value.typeName() == QString("QMapbox::Feature")) {
 #endif
-        return convertGeoJSON(value.value<QMapbox::Feature>());
+        return convertGeoJSON(value.value<QMapbox::Feature>(), error);
     } else if (value.type() != QVariant::ByteArray) {
-        return Error { "JSON data must be in QByteArray" };
+        error = { "JSON data must be in QByteArray" };
+        return {};
     }
 
     auto data = value.toByteArray();
@@ -208,13 +209,14 @@ Result<GeoJSON> convertGeoJSON(const QVariant& value) {
     if (d.HasParseError()) {
         std::stringstream message;
         message << d.GetErrorOffset() << " - " << rapidjson::GetParseError_En(d.GetParseError());
-
-        return Error { message.str() };
+        error = { message.str() };
+        return {};
     }
 
-    Result<GeoJSON> geoJSON = convertGeoJSON<JSValue>(d);
+    optional<GeoJSON> geoJSON = convertGeoJSON<JSValue>(d, error);
     if (!geoJSON) {
-        return Error { geoJSON.error().message };
+        error = { error.message };
+        return {};
     }
 
     return geoJSON;