From d97769fc2b9b54c6fe8235b0fcd0cd4a0b7e1fa7 Mon Sep 17 00:00:00 2001
From: Determinant <ted.sybil@gmail.com>
Date: Fri, 9 Mar 2018 14:42:02 -0500
Subject: use custom (non-thread-safe) impl instead of shared_ptr

---
 promise.hpp | 43 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/promise.hpp b/promise.hpp
index 9fb6170..d3cc7df 100644
--- a/promise.hpp
+++ b/promise.hpp
@@ -121,17 +121,34 @@ namespace promise {
                          ArgType>::value>;
 
     class Promise;
-    class promise_t: public std::shared_ptr<Promise> {
+    //class promise_t: public std::shared_ptr<Promise> {
+    class promise_t {
+        Promise *pm;
+        size_t *ref_cnt;
         public:
         friend Promise;
         template<typename PList> friend promise_t all(const PList &promise_list);
         template<typename PList> friend promise_t race(const PList &promise_list);
 
         promise_t() = delete;
-        template<typename Func>
-        promise_t(Func callback):
-            std::shared_ptr<Promise>(std::make_shared<Promise>()) {
-            callback(*this);
+        promise_t &operator=(const promise_t &other) = delete;
+        template<typename Func> inline promise_t(Func callback);
+        inline ~promise_t();
+
+        promise_t(const promise_t &other):
+            pm(other.pm),
+            ref_cnt(other.ref_cnt) {
+            ++*ref_cnt;
+        }
+
+        promise_t(promise_t &&other):
+            pm(other.pm),
+            ref_cnt(other.ref_cnt) {
+            other.pm = nullptr;
+        }
+
+        Promise *operator->() const {
+            return pm;
         }
 
         template<typename T> inline void resolve(T result) const;
@@ -415,6 +432,22 @@ namespace promise {
         });
     }
 
+    template<typename Func>
+    inline promise_t::promise_t(Func callback):
+            pm(new Promise()),
+        ref_cnt(new size_t(1)) {
+        callback(*this);
+    }
+
+    inline promise_t::~promise_t() {
+        if (pm)
+        {
+            if (--*ref_cnt) return;
+            delete pm;
+            delete ref_cnt;
+        }
+    }
+
     template<typename T>
     inline void promise_t::resolve(T result) const { (*this)->resolve(result); }
 
-- 
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