add new signal API

ostd/signal.hh

@@ -0,0 +1,79 @@
+/* Signals/slots for OctaSTD.
+ *
+ * This file is part of OctaSTD. See COPYING.md for futher information.
+ */
+
+#ifndef OSTD_SIGNAL_HH
+#define OSTD_SIGNAL_HH
+
+#include "ostd/functional.hh"
+#include "ostd/utility.hh"
+
+namespace ostd {
+
+template<typename C, typename ...A>
+struct Event {
+    Event(C *cl = nullptr): p_class(cl), p_funcs(nullptr), p_nfuncs(0) {}
+
+    Event(const Event &ev): p_class(ev.p_class), p_nfuncs(ev.p_nfuncs) {
+        using Func = Function<void(C &, A...)>;
+        Func *nbuf = (Func *)new byte[sizeof(Func) * p_nfuncs];
+        for (Size i = 0; i < p_nfuncs; ++i)
+            new (&nbuf[i]) Func(ev.p_funcs[i]);
+        p_funcs = nbuf;
+    }
+
+    Event(Event &&ev): p_class(ev.p_class), p_funcs(ev.p_funcs),
+                       p_nfuncs(ev.p_nfuncs) {
+        ev.p_class = nullptr;
+        ev.p_funcs = nullptr;
+        ev.p_nfuncs = 0;
+    }
+
+    ~Event() {
+        for (Size i = 0; i < p_nfuncs; ++i)
+            p_funcs[i].~Function<void(C &, A...)>();
+        delete[] (byte *)p_funcs;
+    }
+
+    template<typename F>
+    Size connect(F func) {
+        using Func = Function<void(C &, A...)>;
+        Func *nbuf = (Func *)new byte[sizeof(Func) * (p_nfuncs + 1)];
+        for (Size i = 0; i < p_nfuncs; ++i) {
+            new (&nbuf[i]) Func(move(p_funcs[i]));
+            p_funcs[i].~Func();
+        }
+        new (&nbuf[p_nfuncs]) Func(func);
+        delete[] (byte *)p_funcs;
+        p_funcs = nbuf;
+        return p_nfuncs++;
+    }
+
+    bool disconnect(Size idx) {
+        if ((idx >= p_nfuncs) || !p_funcs[idx]) return false;
+        p_funcs[idx] = nullptr;
+        return true;
+    }
+
+    template<typename ...Args>
+    void emit(Args &&...args) {
+        if (!p_class) return;
+        for (Size i = 0; i < p_nfuncs; ++i)
+            if (p_funcs[i]) p_funcs[i](*p_class, args...);
+    }
+
+    template<typename ...Args>
+    void operator()(Args &&...args) {
+        emit(forward<Args>(args)...);
+    }
+
+private:
+    C *p_class;
+    Function<void(C &, A...)> *p_funcs;
+    Size p_nfuncs;
+};
+
+} /* namespace ostd */
+
+#endif