refs #624 Use auto function return type deduction.

src/blackmisc/aviation/callsignobjectlist.cpp

@@ -93,7 +93,7 @@ namespace BlackMisc
             CONTAINER r;
             if (suffix.isEmpty()) { return r; }
             QString sfxUpper(suffix.trimmed().toUpper());
-            r = this->container().findBy([ = ](const OBJ & csObj) -> bool
+            r = this->container().findBy([ = ](const OBJ & csObj)
             {
                 return (csObj.getCallsign().getSuffix() == sfxUpper);
             });

src/blackmisc/iterator.h

@@ -53,16 +53,16 @@ namespace BlackMisc
             //! @}
 
             //! Return the value at this iterator position.
-            auto value() const -> decltype(std::declval<I>().value()) { return m_iterator.value(); }
+            auto value() const { return m_iterator.value(); }
 
             //! Return the key at this iterator position.
             //! @{
-            auto key() const -> decltype(std::declval<I>().key()) { return m_iterator.key(); }
+            auto key() const { return m_iterator.key(); }
-            auto operator *() const -> decltype(std::declval<I>().key()) { return key(); }
+            auto operator *() const { return key(); }
             //! @}
 
             //! Indirection operator: pointer to the key at this iterator position.
-            auto operator ->() const -> typename std::remove_reference<decltype(std::declval<I>().key())>::type * { return &key(); }
+            auto operator ->() const { return &key(); }
 
             //! Equality operators.
             //! @{

src/blackmisc/lockfree.h

@@ -275,7 +275,7 @@ namespace BlackMisc
 
         //! Pass the current value to the functor inspector, and return whatever inspector returns.
         template <typename F>
-        auto read(F &&inspector) -> decltype(inspector(std::declval<const T &>()))
+        auto read(F &&inspector)
         {
             return std::forward<F>(inspector)(read().get());
         }
@@ -314,14 +314,14 @@ namespace BlackMisc
         //! \param function The LockFree values from which this LockFreeMulti was constructed will be passed as arguments to this functor.
         //! \return The value returned by the functor, if any.
         template <typename F>
-        auto operator ()(F &&function) && -> decltype(function(std::declval<Ts>()...))
+        auto operator ()(F &&function) &&
         {
             return call(std::forward<F>(function), Private::make_index_sequence<sizeof...(Ts)>());
         }
 
     private:
         template <typename F, size_t... Is>
-        auto call(F &&function, Private::index_sequence<Is...>) -> decltype(function(std::declval<Ts>()...))
+        auto call(F &&function, Private::index_sequence<Is...>)
         {
             return std::forward<F>(function)(std::get<Is>(m_tup).get()...);
         }

src/blackmisc/predicates.h

@@ -71,31 +71,6 @@ namespace BlackMisc
                 template <class T> bool operator()(const T &a, const T &b) const { return head.isStable(a, b) ? head(a, b) : tail(a, b); }
             };
 
-            //! \private
-            template <class T, class M> struct MemberTransform
-            {
-                M m;
-                MemberTransform(M m_) : m(m_) {}
-                auto operator()(const T &v) const -> decltype((v.*std::declval<M>())()) { return (v.*m)(); }
-            };
-
-            //! \private
-            template <class T, class M> struct MemberValid
-            {
-                M m;
-                MemberValid(M m_) : m(m_) {}
-                bool operator()(const T &v) const { return (v.*m)().isValid(); }
-            };
-
-            //! \private
-            template <class T, class M, class C> struct MemberIsAnyOf
-            {
-                M m;
-                const C &c;
-                MemberIsAnyOf(M m_, const C &c_) : m(m_), c(c_) {}
-                bool operator()(const T &v) const { return c.contains((v.*m)()); }
-            };
-
             //! \private
             template <class T> struct Equals
             {
@@ -137,58 +112,44 @@ namespace BlackMisc
         }
 
         /*!
-         * Transformation function object which returns the value returned by one of it's argument member functions.
+         * Returns a function object that returns the value returned by one of it's argument member functions.
-         *
-         * A lambda would usually be easier, but it is difficult to directly return a lambda from a function
-         * without C++14 deduced return types.
          */
         template <class T, class R>
-        auto MemberTransform(R(T::*memberFunc)() const) -> Private::MemberTransform<T, decltype(memberFunc)>
+        auto MemberTransform(R(T::*memberFunc)() const)
         {
-            return { memberFunc };
+            return [memberFunc](const T &object) { return (object.*memberFunc)(); };
         }
 
         /*!
-         * Predicate which is true if the isValid() method of the value returned from one of its member functions returns true.
+         * Returns a predicate that returns true if the isValid() method of the value returned from one of its member functions returns true.
-         *
-         * A lambda would usually be easier, but it is difficult to directly return a lambda from a function
-         * without C++14 deduced return types.
          */
         template <class T, class R>
-        auto MemberValid(R(T::*memberFunc)() const) -> Private::MemberValid<T, decltype(memberFunc)>
+        auto MemberValid(R(T::*memberFunc)() const)
         {
-            return { memberFunc };
+            return [memberFunc](const T &object) { return (object.*memberFunc)().isValid(); };
         }
 
         /*!
-         * Predicate which is true if the value returned by its argument's member function can be found in a captured container.
+         * Returns a predicate that returns true if the value returned by its argument's member function can be found in a captured container.
-         *
-         * A lambda would usually be easier, but it is difficult to directly return a lambda from a function
-         * without C++14 deduced return types.
-         *
          * \warning The container is captured by reference, so be careful that it remains valid for the lifetime of the predicate.
          */
         template <class T, class R, class C>
-        auto MemberIsAnyOf(R(T::*memberFunc)() const, const C &container) -> Private::MemberIsAnyOf<T, decltype(memberFunc), C>
+        auto MemberIsAnyOf(R(T::*memberFunc)() const, const C &container)
         {
-            return { memberFunc, container };
+            return [memberFunc, &container](const T &object) { return container.contains((object.*memberFunc)()); };
         }
 
         /*!
-         * Predicate which is true if its argument compares equal with another, captured value.
+         * Returns a predicate that returns true if its argument compares equal with another, captured value.
-         *
-         * A lambda would usually be easier, but it is difficult to directly return a lambda from a function
-         * without C++14 deduced return types. It is also a generic function object, which is only possible
-         * with C++14 generic lambdas.
          */
         template <class T>
-        auto Equals(T &&value) -> Private::Equals<typename std::decay<T>::type>
+        auto Equals(T &&value)
         {
-            return { std::forward<T>(value), 0 };
+            return [value = std::forward<T>(value)](const T &object) { return object == value; };
         }
 
         /*!
-         * Predicate which is true if its argument matches a captured CPropertyIndexVariantMap.
+         * Returns a predicate that returns true if its argument matches a captured CPropertyIndexVariantMap.
          */
         inline auto Matches(const CPropertyIndexVariantMap &map) -> Private::Matches
         {

src/blackmisc/simulation/fscommon/aircraftcfgentrieslist.cpp

@@ -27,7 +27,7 @@ namespace BlackMisc
             {
                 if (title.isEmpty()) { return false; }
                 return this->containsBy(
-                           [ = ](const CAircraftCfgEntries & entries) -> bool { return title.compare(entries.getTitle(), caseSensitivity) == 0; }
+                           [ = ](const CAircraftCfgEntries & entries) { return title.compare(entries.getTitle(), caseSensitivity) == 0; }
                        );
             }
 
@@ -82,7 +82,7 @@ namespace BlackMisc
 
             CAircraftCfgEntriesList CAircraftCfgEntriesList::findByTitle(const QString &title, Qt::CaseSensitivity caseSensitivity) const
             {
-                return this->findBy([ = ](const CAircraftCfgEntries & entries) -> bool
+                return this->findBy([ = ](const CAircraftCfgEntries & entries)
                 { return title.compare(entries.getTitle(), caseSensitivity) == 0; });
             }
 

src/blackmisc/tuple.h

@@ -75,21 +75,21 @@ namespace BlackMisc
             friend class BlackMisc::Private::EncapsulationBreaker;              \
             static_assert(Private::HasEnabledTupleConversion<T>::value,         \
                           "Missing BLACK_ENABLE_TUPLE_CONVERSION macro in " #T); \
-            static auto toTuple(const T &o) -> decltype(BlackMisc::tie MEMBERS) \
+            static auto toTuple(const T &o)                                     \
             {                                                                   \
                 return BlackMisc::tie MEMBERS;                                  \
             }                                                                   \
-            static auto toTuple(T &o) -> decltype(BlackMisc::tie MEMBERS)       \
+            static auto toTuple(T &o)                                           \
             {                                                                   \
                 return BlackMisc::tie MEMBERS;                                  \
             }                                                                   \
-            static auto toMetaTuple(const T &o) -> decltype(BlackMisc::tieMeta MEMBERS) \
+            static auto toMetaTuple(const T &o)                                 \
             {                                                                   \
                 auto tu = BlackMisc::tieMeta MEMBERS;                           \
                 parser().extendMetaTuple(tu);                                   \
                 return tu;                                                      \
             }                                                                   \
-            static auto toMetaTuple(T &o) -> decltype(BlackMisc::tieMeta MEMBERS) \
+            static auto toMetaTuple(T &o)                                       \
             {                                                                   \
                 auto tu = BlackMisc::tieMeta MEMBERS;                           \
                 parser().extendMetaTuple(tu);                                   \
@@ -105,7 +105,7 @@ namespace BlackMisc
                 return parser().m_names;                                        \
             }                                                                   \
         public:                                                                 \
-            static auto constToTuple(const T &o) -> decltype(BlackMisc::tie MEMBERS) \
+            static auto constToTuple(const T &o)                                \
             {                                                                   \
                 return BlackMisc::tie MEMBERS;                                  \
             }                                                                   \
@@ -127,21 +127,21 @@ namespace BlackMisc
             friend class BlackMisc::Private::EncapsulationBreaker;              \
             static_assert(Private::HasEnabledTupleConversion<T<U...>>::value,   \
                           "Missing BLACK_ENABLE_TUPLE_CONVERSION macro in " #T); \
-            static auto toTuple(const T<U...> &o) -> decltype(BlackMisc::tie MEMBERS) \
+            static auto toTuple(const T<U...> &o)                               \
             {                                                                   \
                 return BlackMisc::tie MEMBERS;                                  \
             }                                                                   \
-            static auto toTuple(T<U...> &o) -> decltype(BlackMisc::tie MEMBERS) \
+            static auto toTuple(T<U...> &o)                                     \
             {                                                                   \
                 return BlackMisc::tie MEMBERS;                                  \
             }                                                                   \
-            static auto toMetaTuple(const T<U...> &o) -> decltype(BlackMisc::tieMeta MEMBERS) \
+            static auto toMetaTuple(const T<U...> &o)                           \
             {                                                                   \
                 auto tu = BlackMisc::tieMeta MEMBERS;                           \
                 parser().extendMetaTuple(tu);                                   \
                 return tu;                                                      \
             }                                                                   \
-            static auto toMetaTuple(T<U...> &o) -> decltype(BlackMisc::tieMeta MEMBERS) \
+            static auto toMetaTuple(T<U...> &o)                                 \
             {                                                                   \
                 auto tu = BlackMisc::tieMeta MEMBERS;                           \
                 parser().extendMetaTuple(tu);                                   \
@@ -157,7 +157,7 @@ namespace BlackMisc
                 return parser().m_names;                                        \
             }                                                                   \
         public:                                                                 \
-            static auto constToTuple(const T<U...> &o) -> decltype(BlackMisc::tie MEMBERS) \
+            static auto constToTuple(const T<U...> &o)                          \
             {                                                                   \
                 return BlackMisc::tie MEMBERS;                                  \
             }                                                                   \
@@ -286,7 +286,7 @@ namespace BlackMisc
      * \ingroup Tuples
      */
     template <class... Ts>
-    auto tie(Ts &&... args) -> decltype(std::make_tuple(Private::tieHelper(args)...))
+    auto tie(Ts &&... args)
     {
         return std::make_tuple(Private::tieHelper(args)...);
     }
@@ -296,7 +296,7 @@ namespace BlackMisc
      * \ingroup Tuples
      */
     template <class... Ts>
-    auto tieMeta(Ts &&... args) -> decltype(std::make_tuple(Private::tieMetaHelper(args)...))
+    auto tieMeta(Ts &&... args)
     {
         return std::make_tuple(Private::tieMetaHelper(args)...);
     }

src/blackmisc/tupleprivate.h

@@ -40,7 +40,7 @@ namespace BlackMisc
         {
         protected:
             template <class T>
-            static auto toMetaTuple(T &o) -> decltype(TupleConverter<typename std::decay<T>::type>::toMetaTuple(o))
+            static auto toMetaTuple(T &o)
             {
                 return TupleConverter<typename std::decay<T>::type>::toMetaTuple(o);
             }
@@ -213,14 +213,14 @@ namespace BlackMisc
 
         // Convert a meta tuple to a value tuple
         template <class Tu, size_t... Is>
-        auto stripMeta(Tu &&tu, index_sequence<Is...>) -> decltype(std::make_tuple(tieHelper(std::get<Is>(std::forward<Tu>(tu)))...))
+        auto stripMeta(Tu &&tu, index_sequence<Is...>)
         {
             return std::make_tuple(tieHelper(std::get<Is>(std::forward<Tu>(tu)))...);
         }
 
         // Convert a value tuple to a meta tuple with default metadata
         template <class Tu, size_t... Is>
-        auto recoverMeta(Tu &&tu, index_sequence<Is...>) -> decltype(std::make_tuple(tieMetaHelper(std::get<Is>(std::forward<Tu>(tu)))...))
+        auto recoverMeta(Tu &&tu, index_sequence<Is...>)
         {
             return std::make_tuple(tieMetaHelper(std::get<Is>(std::forward<Tu>(tu)))...);
         }
@@ -297,7 +297,7 @@ namespace BlackMisc
 
         private:
             template <size_t I, class Tu>
-            static auto get_ref(Tu &&tu) -> decltype(tieHelper(std::get<I>(std::forward<Tu>(tu))))
+            static auto get_ref(Tu &&tu)
             {
                 return tieHelper(std::get<I>(std::forward<Tu>(tu)));
             }

src/blackmisc/valuecache.h

@@ -191,18 +191,14 @@ namespace BlackMisc
         //! If the derived class does not handle such requests, the signal can be ignored.
         void valuesSaveRequested(const BlackMisc::CValueCachePacket &values);
 
-    private:
-        struct Element; // remove forward declaration (and uncomment the one below) when elementsStartingWith uses C++14 auto deduced return type
-
     protected:
         //! Returns a range referring to all elements which start with the given prefix.
-        //! \todo Use C++14 auto deduced return type.
         //! @{
-        CRange<QMap<QString, QSharedPointer<Element>>::iterator> elementsStartingWith(const QString &keyPrefix)
+        auto elementsStartingWith(const QString &keyPrefix)
         {
             return makeRange(m_elements.lowerBound(keyPrefix), m_elements.lowerBound(keyPrefix + QChar(QChar::LastValidCodePoint)));
         }
-        CRange<QMap<QString, QSharedPointer<Element>>::const_iterator> elementsStartingWith(const QString &keyPrefix) const
+        auto elementsStartingWith(const QString &keyPrefix) const
         {
             return makeRange(m_elements.lowerBound(keyPrefix), m_elements.lowerBound(keyPrefix + QChar(QChar::LastValidCodePoint)));
         }
@@ -234,7 +230,7 @@ namespace BlackMisc
 
     private:
         friend class Private::CValuePage;
-        // struct Element; // to be uncommented when the forward declaration above elementsStartingWith is removed
+        struct Element;
         using ElementPtr = QSharedPointer<Element>; // QMap doesn't support move-only types
 
         QMap<QString, ElementPtr> m_elements;