Common/Functional: Fix MoveOnlyFunction from inadvertently creating references from lvalues.

1 files changed, 7 insertions, 4 deletions

diff --git a/Source/Core/Common/Functional.h b/Source/Core/Common/Functional.h
index 49d81d5a24..cdb44ebb0c 100644
--- a/Source/Core/Common/Functional.h
+++ b/Source/Core/Common/Functional.h
@@ -3,7 +3,9 @@
 
 #pragma once
 
+#include <concepts>
 #include <memory>
+#include <type_traits>
 
 // TODO C++23: Replace with std::move_only_function.
 
@@ -21,13 +23,14 @@ public:
 
   MoveOnlyFunction() = default;
 
-  template <typename F>
+  template <std::invocable<Args...> F>
+  requires(!std::same_as<std::decay_t<F>, MoveOnlyFunction>)
   MoveOnlyFunction(F&& f) : m_ptr{std::make_unique<Func<F>>(std::forward<F>(f))}
   {
   }
 
   result_type operator()(Args... args) const { return m_ptr->Invoke(std::forward<Args>(args)...); }
-  explicit operator bool() const { return m_ptr != nullptr; };
+  explicit operator bool() const { return m_ptr != nullptr; }
   void swap(MoveOnlyFunction& other) { m_ptr.swap(other.m_ptr); }
 
 private:
@@ -40,9 +43,9 @@ private:
   template <typename F>
   struct Func : FuncBase
   {
-    Func(F&& f) : func{std::forward<F>(f)} {}
+    explicit Func(F&& f) : func{std::forward<F>(f)} {}
     result_type Invoke(Args... args) override { return func(std::forward<Args>(args)...); }
-    F func;
+    std::decay_t<F> func;
   };
 
   std::unique_ptr<FuncBase> m_ptr;