Enable QPromise<T>::resolve() by reference

src/qtpromise/qpromise.h

@@ -88,6 +88,7 @@ public: // STATIC
     template <template <typename, typename...> class Sequence = QVector, typename ...Args>
     inline static QPromise<QVector<T> > all(const Sequence<QPromise<T>, Args...>& promises);
 
+    inline static QPromise<T> resolve(const T& value);
     inline static QPromise<T> resolve(T&& value);
 
 private:

src/qtpromise/qpromise.inl

@@ -244,6 +244,14 @@ inline QPromise<QVector<T> > QPromise<T>::all(const Sequence<QPromise<T>, Args..
     });
 }
 
+template <typename T>
+inline QPromise<T> QPromise<T>::resolve(const T& value)
+{
+    return QPromise<T>([&](const QPromiseResolve<T>& resolve) {
+       resolve(value);
+    });
+}
+
 template <typename T>
 inline QPromise<T> QPromise<T>::resolve(T&& value)
 {

tests/auto/qtpromise/benchmark/tst_benchmark.cpp

@@ -20,6 +20,7 @@ class tst_benchmark : public QObject
 
 private Q_SLOTS:
     void valueResolve();
+    void valueResolveStatic();
     void valueReject();
     void valueThen();
     void valueFinally();
@@ -126,6 +127,31 @@ void tst_benchmark::valueResolve()
     }
 }
 
+void tst_benchmark::valueResolveStatic()
+{
+    {   // should move the value when resolved by rvalue
+        Data::logs().reset();
+        QPromise<Data>::resolve(Data(42)).wait();
+
+        QCOMPARE(Data::logs().ctor, 1);
+        QCOMPARE(Data::logs().copy, 0);
+        QCOMPARE(Data::logs().move, 1);     // move value to the promise data
+        QCOMPARE(Data::logs().refs, 0);
+    }
+    {   // should create one copy of the value when resolved by lvalue
+        {
+            Data::logs().reset();
+            Data value(42);
+            QPromise<Data>::resolve(value).wait();
+        }
+
+        QCOMPARE(Data::logs().ctor, 1);
+        QCOMPARE(Data::logs().copy, 1);     // copy value to the promise data
+        QCOMPARE(Data::logs().move, 0);
+        QCOMPARE(Data::logs().refs, 0);
+    }
+}
+
 void tst_benchmark::valueReject()
 {
     {   // should not create any data if rejected

tests/auto/qtpromise/qpromise/qpromise.pro

@@ -6,6 +6,7 @@ SUBDIRS += \
     fail \
     finally \
     operators \
+    resolve \
     tap \
     then \
     timeout

tests/auto/qtpromise/qpromise/resolve/resolve.pro

@@ -0,0 +1,4 @@
+TARGET = tst_qpromise_resolve
+SOURCES += $$PWD/tst_resolve.cpp
+
+include(../../qtpromise.pri)

tests/auto/qtpromise/qpromise/resolve/tst_resolve.cpp

@@ -0,0 +1,41 @@
+// Tests
+#include "../../shared/utils.h"
+
+// QtPromise
+#include <QtPromise>
+
+// Qt
+#include <QtTest>
+
+using namespace QtPromise;
+
+class tst_qpromise_resolve : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void value();
+    void empty_void();
+};
+
+QTEST_MAIN(tst_qpromise_resolve)
+#include "tst_resolve.moc"
+
+void tst_qpromise_resolve::value()
+{
+    const int value = 42;
+    auto p0 = QPromise<int>::resolve(value);
+    auto p1 = QPromise<int>::resolve(43);
+
+    QCOMPARE(p0.isFulfilled(), true);
+    QCOMPARE(p1.isFulfilled(), true);
+    QCOMPARE(waitForValue(p0, -1), 42);
+    QCOMPARE(waitForValue(p1, -1), 43);
+}
+
+void tst_qpromise_resolve::empty_void()
+{
+    auto p = QPromise<void>::resolve();
+
+    QCOMPARE(p.isFulfilled(), true);
+}