Fixed strange compile error when using QMovedResult::value() instead of

explicitely constructing it...

tests/QBind/QJson_impl.h

@@ -110,44 +110,44 @@ private:
 };
 QJsonBuilder::QJsonBuilder(QJsonValue* v) : QScopedResult(new QJsonBuilderImpl(v), true) {}
 
-//class JsonVisitor : public QMovedResult<JsonVisitor, BindMode::Read>
-//{
-//protected:
-//    JsonVisitor(const JsonVisitor &o) : QMovedResult(), value(o.current()), steps(o.steps) {}
-//    JsonVisitor &operator=(const JsonVisitor &) = delete;
-//public:
-//    Q_ENABLE_MOVE(JsonVisitor, std::swap(value, o.value); std::swap(steps, o.steps); )
-//    JsonVisitor(const QJsonValue* v) : value(v) { Q_ASSERT(v); }
-//
-//    operator bool() { return value; } // for QMovedResult
-//protected:
-//    friend class QMovedResult<JsonVisitor, BindMode::Read>; // for slight optimization of fluent interface shortcuts
-//    template<class T_> friend class Val; // calls methods below
-//
-//    bool           _null() { if (current()->isNull  ()) {                            return true; } return false; }
-//    bool         _record() { if (current()->isObject()) {        steps.push(Step()); return true; } return false; }
-//    bool       _sequence() { if (current()->isArray ()) {        steps.push(Step()); return true; } return false; }
-//    bool _bind(QString& v) { if (current()->isString()) { v = current()->toString(); return true; } return false; }
-//    bool _bind( double& v) { if (current()->isDouble()) { v = current()->toDouble(); return true; } return false; }
-//    bool _bind(   bool& v) { if (current()->isBool  ()) { v = current()->toBool  (); return true; } return false; }
-//
-//    //template<typename T> bool _bind(T& t, std::enable_if_t<std::is_arithmetic<T>::value>* = nullptr) { double d; if (_bind(d)) { t = d; return true; } return false; }
-//
-//    // Val<TResult> prevents QBind from getting out() of an outer Seq for instance
-//    template<typename T> bool _bind(T& t) { return QBind<TResult,T>::bind(TResult(*this).value(), t); }
-//
-//    template<class T_> friend class Seq; // calls methods below
-//
-//    bool _item(const char* key) { steps.last().key=key; steps.last().item=current(1)->toObject()[QString::fromUtf8(steps.last().key)]; return true; }
-//    bool _item(               ) { steps.last().idx++  ; steps.last().item=current(1)->toArray ()[                  steps.last().idx ]; return true; }
-//    bool                 _out() { steps.pop(); return true; }
-//private:
-//    const QJsonValue* current(unsigned outer=0) const { return steps.size()-outer <= 0 ? value : &(steps[steps.size()-outer-1].item); }
-//
-//    const QJsonValue* value;
-//    struct Step { const char* key=nullptr; int idx=-1; QJsonValue item; Step() = default; };
-//    QStack<Step> steps = QStack<Step>();
-//};
+class JsonVisitor : public QMovedResult<JsonVisitor, BindMode::Read>
+{
+protected:
+    JsonVisitor(const JsonVisitor &o) : QMovedResult(), value(o.current()), steps(o.steps) {}
+    JsonVisitor &operator=(const JsonVisitor &) = delete;
+public:
+    Q_ENABLE_MOVE(JsonVisitor, std::swap(value, o.value); std::swap(steps, o.steps); )
+    JsonVisitor(const QJsonValue* v) : value(v) { Q_ASSERT(v); }
+
+    operator bool() { return value; } // for QMovedResult
+protected:
+    friend class QMovedResult<JsonVisitor, BindMode::Read>; // for slight optimization of fluent interface shortcuts
+    template<class T_> friend class Val; // calls methods below
+
+    bool           _null() { if (current()->isNull  ()) {                            return true; } return false; }
+    bool         _record() { if (current()->isObject()) {        steps.push(Step()); return true; } return false; }
+    bool       _sequence() { if (current()->isArray ()) {        steps.push(Step()); return true; } return false; }
+    bool _bind(QString& v) { if (current()->isString()) { v = current()->toString(); return true; } return false; }
+    bool _bind( double& v) { if (current()->isDouble()) { v = current()->toDouble(); return true; } return false; }
+    bool _bind(   bool& v) { if (current()->isBool  ()) { v = current()->toBool  (); return true; } return false; }
+
+    //template<typename T> bool _bind(T& t, std::enable_if_t<std::is_arithmetic<T>::value>* = nullptr) { double d; if (_bind(d)) { t = d; return true; } return false; }
+
+    // Val<TResult> prevents QBind from getting out() of an outer Seq for instance
+    template<typename T> bool _bind(T& t) { return QBind<TResult,T>::bind(Val<TResult>(TResult(*this)), t); } // TODO check why .value() does not work
+
+    template<class T_> friend class Seq; // calls methods below
+
+    bool _item(const char* key) { steps.last().key=key; steps.last().item=current(1)->toObject()[QString::fromUtf8(steps.last().key)]; return true; }
+    bool _item(               ) { steps.last().idx++  ; steps.last().item=current(1)->toArray ()[                  steps.last().idx ]; return true; }
+    bool                 _out() { steps.pop(); return true; }
+private:
+    const QJsonValue* current(unsigned outer=0) const { return steps.size()-outer <= 0 ? value : &(steps[steps.size()-outer-1].item); }
+
+    const QJsonValue* value;
+    struct Step { const char* key=nullptr; int idx=-1; QJsonValue item; Step() = default; };
+    QStack<Step> steps = QStack<Step>();
+};
 
 class QJsonWriterImpl;
 class QJsonWriter : public QScopedResult<QJsonWriter, QJsonWriterImpl, BindMode::Write>

tests/QBind/main.cpp

@@ -311,10 +311,11 @@ int main()
             QJsonBuilder(&v).bind(p);
         }
         STOP("T>JsonValue",QString::fromUtf8(QJsonDocument(v.toArray()).toJson()));
-//        START {
-//            JsonVisitor(&v).bind(p);
-//        }
-//        STOP("JsonValue>T",QString("[%1,%2,%3,[..%4..]] errors:%5").arg(p.firstName,p.lastName).arg(p.height).arg(p.phones.size()).arg(errors.size()))
+        START {
+            p = {};
+            JsonVisitor(&v).bind(p);
+        }
+        STOP("JsonValue>T",QString("[%1,%2,%3,[..%4..]] errors:%5").arg(p.firstName,p.lastName).arg(p.height).arg(p.phones.size()).arg(errors.size()))
         START {
             json.seek(0); v = QJsonValue();
             errors = QJsonReader(&json).bind(v)->errors;