From 492fa7c6320bff355a9e8b82e5578d94d4506a3a Mon Sep 17 00:00:00 2001
From: oltolm <oleg.tolmatcev@gmail.com>
Date: Fri, 21 Nov 2025 00:00:03 +0100
Subject: [PATCH] use concepts instead of SFINAE

---
 src/xenia/base/chrono.h            | 23 ++++++++++-------------
 src/xenia/kernel/util/shim_utils.h | 15 ++++++++-------
 src/xenia/kernel/xobject.h         |  8 ++++----
 3 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/src/xenia/base/chrono.h b/src/xenia/base/chrono.h
index 1e9e0ea05..9812d1253 100644
--- a/src/xenia/base/chrono.h
+++ b/src/xenia/base/chrono.h
@@ -75,11 +75,10 @@ struct NtSystemClock {
   }
 
   // To convert XSystemClock to sys, do clock_cast<WinSystemTime>(tp) first
-  // SFINAE hack https://stackoverflow.com/a/58813009
-  template <Domain domain_fresh_ = domain_>
-  static constexpr std::enable_if_t<domain_fresh_ == Domain::Host,
-                                    std::chrono::system_clock::time_point>
-  to_sys(const time_point& tp) {
+  static constexpr std::chrono::system_clock::time_point to_sys(
+      const time_point& tp)
+    requires(domain_ == Domain::Host)
+  {
     using sys_duration = std::chrono::system_clock::duration;
     using sys_time = std::chrono::system_clock::time_point;
 
@@ -91,17 +90,15 @@ struct NtSystemClock {
 
   // TODO(Gliniak): Disable until WINE will implement tzdb.
   /*
-  template <Domain domain_fresh_ = domain_>
-  static constexpr std::enable_if_t<
-      domain_fresh_ == Domain::Host,
-      std::chrono::local_time<std::chrono::system_clock::duration>>
-  to_local(const time_point& tp) {
+  static constexpr std::chrono::local_time<std::chrono::system_clock::duration>
+  to_local(const time_point& tp) requires (domain_ == Domain::Host) {
     return std::chrono::current_zone()->to_local(to_sys(tp));
   }*/
 
-  template <Domain domain_fresh_ = domain_>
-  static constexpr std::enable_if_t<domain_fresh_ == Domain::Host, time_point>
-  from_sys(const std::chrono::system_clock::time_point& tp) {
+  static constexpr time_point from_sys(
+      const std::chrono::system_clock::time_point& tp)
+    requires(domain_ == Domain::Host)
+  {
     auto ctp = std::chrono::time_point_cast<duration>(tp);
     auto dp = time_point{ctp.time_since_epoch()};
     dp -= unix_epoch_delta();
diff --git a/src/xenia/kernel/util/shim_utils.h b/src/xenia/kernel/util/shim_utils.h
index 31aa85ec5..4af7166d4 100644
--- a/src/xenia/kernel/util/shim_utils.h
+++ b/src/xenia/kernel/util/shim_utils.h
@@ -500,15 +500,16 @@ enum class KernelModuleId {
 };
 
 template <size_t I = 0, typename... Ps>
-typename std::enable_if<I == sizeof...(Ps)>::type AppendKernelCallParams(
-    StringBuffer& string_buffer, xe::cpu::Export* export_entry,
-    const std::tuple<Ps...>&) {}
+  requires(I == sizeof...(Ps))
+void AppendKernelCallParams(StringBuffer& string_buffer,
+                            xe::cpu::Export* export_entry,
+                            const std::tuple<Ps...>&) {}
 
 template <size_t I = 0, typename... Ps>
-    typename std::enable_if <
-    I<sizeof...(Ps)>::type AppendKernelCallParams(
-        StringBuffer& string_buffer, xe::cpu::Export* export_entry,
-        const std::tuple<Ps...>& params) {
+  requires(I < sizeof...(Ps))
+void AppendKernelCallParams(StringBuffer& string_buffer,
+                            xe::cpu::Export* export_entry,
+                            const std::tuple<Ps...>& params) {
   if (I) {
     string_buffer.Append(", ");
   }
diff --git a/src/xenia/kernel/xobject.h b/src/xenia/kernel/xobject.h
index e3413622c..be6fe036d 100644
--- a/src/xenia/kernel/xobject.h
+++ b/src/xenia/kernel/xobject.h
@@ -286,8 +286,8 @@ class object_ref {
     reset(right.get());
     if (value_) value_->Retain();
   }
-  template <class V, class = typename std::enable_if<
-                         std::is_convertible<V*, T*>::value, void>::type>
+  template <class V>
+    requires std::is_convertible_v<V*, T*>
   object_ref(const object_ref<V>& right) noexcept {
     reset(right.get());
     if (value_) value_->Retain();
@@ -379,8 +379,8 @@ bool operator!=(std::nullptr_t _Left, const object_ref<_Ty>& _Right) noexcept {
 }
 
 template <class T, class... Args>
-std::enable_if_t<!std::is_array<T>::value, object_ref<T>> make_object(
-    Args&&... args) {
+  requires(!std::is_array_v<T>)
+object_ref<T> make_object(Args&&... args) {
   return object_ref<T>(new T(std::forward<Args>(args)...));
 }