From 8dd4a066ca0312ff03595b96a75abc8c6123f576 Mon Sep 17 00:00:00 2001
From: Daniel Wilhelm <shieldwed@outlook.com>
Date: Sat, 29 Oct 2016 11:35:33 +0200
Subject: 8.5

---
 zen/scope_guard.h | 64 ++++++++++++++++++++++---------------------------------
 1 file changed, 25 insertions(+), 39 deletions(-)

(limited to 'zen/scope_guard.h')

diff --git a/zen/scope_guard.h b/zen/scope_guard.h
index 69d4b060..8ab58901 100644
--- a/zen/scope_guard.h
+++ b/zen/scope_guard.h
@@ -9,9 +9,7 @@
 
 #include <cassert>
 #include <exception>
-#include <type_traits> //std::decay
-
-//best of Zen, Loki and C++17
+#include "type_tools.h"
 
 
 #ifdef ZEN_WIN
@@ -20,9 +18,9 @@ inline int getUncaughtExceptionCount() { return std::uncaught_exceptions(); }
 #elif defined ZEN_LINUX || defined ZEN_MAC
 //std::uncaught_exceptions() currently unsupported on GCC and Clang => clean up ASAP
 #ifdef ZEN_LINUX
-    static_assert(__GNUC__ < 6 || (__GNUC__ == 6 && (__GNUC_MINOR__ < 1 || (__GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1))), "check std::uncaught_exceptions support");
-#else
-    static_assert(__clang_major__ < 7 || (__clang_major__ == 7 && __clang_minor__ <= 3), "check std::uncaught_exceptions support");
+    static_assert(__GNUC__ < 6 || (__GNUC__ == 6 && (__GNUC_MINOR__ < 2 || (__GNUC_MINOR__ == 2 && __GNUC_PATCHLEVEL__ <= 1))), "check std::uncaught_exceptions support");
+#else //std::uncaught_exceptions() requires "mmacosx-version-min=10.12"
+    static_assert(__clang_major__ < 8 || (__clang_major__ == 8 && __clang_minor__ <= 0), "check std::uncaught_exceptions support");
 #endif
 
 namespace __cxxabiv1
@@ -37,6 +35,7 @@ inline int getUncaughtExceptionCount()
 }
 #endif
 
+//best of Zen, Loki and C++17
 
 namespace zen
 {
@@ -60,45 +59,32 @@ enum class ScopeGuardRunMode
 };
 
 
-template <ScopeGuardRunMode runMode, typename F>
-struct ScopeGuardDestructor;
-
-//specialize scope guard destructor code and get rid of those pesky MSVC "4127 conditional expression is constant"
-template <typename F>
-struct ScopeGuardDestructor<ScopeGuardRunMode::ON_EXIT, F>
+//partially specialize scope guard destructor code and get rid of those pesky MSVC "4127 conditional expression is constant"
+template <typename F> inline
+void runScopeGuardDestructor(F& fun, int /*exeptionCountOld*/, StaticEnum<ScopeGuardRunMode, ScopeGuardRunMode::ON_EXIT>)
 {
-    static void run(F& fun, int exeptionCountOld)
-    {
-		(void)exeptionCountOld; //silence unused parameter warning
-        try { fun(); }
-        catch (...) { assert(false); } //consistency: don't expect exceptions for ON_EXIT even if "!failed"!
-    }
-};
+    try { fun(); }
+    catch (...) { assert(false); } //consistency: don't expect exceptions for ON_EXIT even if "!failed"!
+}
 
 
-template <typename F>
-struct ScopeGuardDestructor<ScopeGuardRunMode::ON_SUCCESS, F>
+template <typename F> inline
+void runScopeGuardDestructor(F& fun, int exeptionCountOld, StaticEnum<ScopeGuardRunMode, ScopeGuardRunMode::ON_SUCCESS>)
 {
-    static void run(F& fun, int exeptionCountOld)
-    {
-        const bool failed = getUncaughtExceptionCount() > exeptionCountOld;
-        if (!failed)
-            fun(); //throw X
-    }
-};
+    const bool failed = getUncaughtExceptionCount() > exeptionCountOld;
+    if (!failed)
+        fun(); //throw X
+}
 
 
-template <typename F>
-struct ScopeGuardDestructor<ScopeGuardRunMode::ON_FAIL, F>
+template <typename F> inline
+void runScopeGuardDestructor(F& fun, int exeptionCountOld, StaticEnum<ScopeGuardRunMode, ScopeGuardRunMode::ON_FAIL>)
 {
-    static void run(F& fun, int exeptionCountOld)
-    {
-        const bool failed = getUncaughtExceptionCount() > exeptionCountOld;
-        if (failed)
-            try { fun(); }
-            catch (...) { assert(false); }
-    }
-};
+    const bool failed = getUncaughtExceptionCount() > exeptionCountOld;
+    if (failed)
+        try { fun(); }
+        catch (...) { assert(false); }
+}
 
 
 template <ScopeGuardRunMode runMode, typename F>
@@ -115,7 +101,7 @@ public:
     ~ScopeGuard() noexcept(runMode != ScopeGuardRunMode::ON_SUCCESS)
     {
         if (!dismissed)
-            ScopeGuardDestructor<runMode, F>::run(fun_, exeptionCount);
+            runScopeGuardDestructor(fun_, exeptionCount, StaticEnum<ScopeGuardRunMode, runMode>());
     }
 
     void dismiss() { dismissed = true; }
-- 
cgit