From 5cd4c51f07355a30d583ebb70ffd92b197da9771 Mon Sep 17 00:00:00 2001
From: nerix <nerixdev@outlook.de>
Date: Fri, 26 Jan 2024 21:55:30 +0100
Subject: [PATCH] chore: specialize `Atomic<std::shared_ptr<T>>` (#5133)

---
 CHANGELOG.md          |  1 +
 src/common/Atomic.hpp | 68 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd5457a6..9b95dc20 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -133,6 +133,7 @@
 - Dev: Added benchmark for parsing and building recent messages. (#5071)
 - Dev: Boost is depended on as a header-only library when using conan. (#5107)
 - Dev: Added signal to invalidate paint buffers of channel views without forcing a relayout. (#5123)
+- Dev: Specialize `Atomic<std::shared_ptr<T>>` if underlying standard library supports it. (#5133)
 
 ## 2.4.6
 
diff --git a/src/common/Atomic.hpp b/src/common/Atomic.hpp
index 30943e23..cb6686c5 100644
--- a/src/common/Atomic.hpp
+++ b/src/common/Atomic.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <atomic>
+#include <memory>
 #include <mutex>
 
 namespace chatterino {
@@ -9,9 +11,10 @@ class Atomic
 {
 public:
     Atomic() = default;
+    ~Atomic() = default;
 
     Atomic(T &&val)
-        : value_(val)
+        : value_(std::move(val))
     {
     }
 
@@ -47,4 +50,67 @@ private:
     T value_;
 };
 
+#if defined(__cpp_lib_atomic_shared_ptr) && defined(__cpp_concepts)
+
+template <typename T>
+class Atomic<std::shared_ptr<T>>
+{
+    // Atomic<std::shared_ptr<T>> must be instantated with a const T
+};
+
+template <typename T>
+    requires std::is_const_v<T>
+class Atomic<std::shared_ptr<T>>
+{
+public:
+    Atomic() = default;
+    ~Atomic() = default;
+
+    Atomic(T &&val)
+        : value_(std::make_shared<T>(std::move(val)))
+    {
+    }
+
+    Atomic(std::shared_ptr<T> &&val)
+        : value_(std::move(val))
+    {
+    }
+
+    Atomic(const Atomic &) = delete;
+    Atomic &operator=(const Atomic &) = delete;
+
+    Atomic(Atomic &&) = delete;
+    Atomic &operator=(Atomic &&) = delete;
+
+    std::shared_ptr<T> get() const
+    {
+        return this->value_.load();
+    }
+
+    void set(const T &val)
+    {
+        this->value_.store(std::make_shared<T>(val));
+    }
+
+    void set(T &&val)
+    {
+        this->value_.store(std::make_shared<T>(std::move(val)));
+    }
+
+    void set(const std::shared_ptr<T> &val)
+    {
+        this->value_.store(val);
+    }
+
+    void set(std::shared_ptr<T> &&val)
+    {
+        this->value_.store(std::move(val));
+    }
+
+private:
+    std::atomic<std::shared_ptr<T>> value_;
+};
+
+#endif
+
 }  // namespace chatterino