1 files changed, 89 insertions, 0 deletions
diff --git a/zen/legacy_compiler.h b/zen/legacy_compiler.h
new file mode 100755
index 00000000..5a0013b3
--- /dev/null
+++ b/zen/legacy_compiler.h
@@ -0,0 +1,89 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#ifndef LEGACY_COMPILER_H_839567308565656789
+#define LEGACY_COMPILER_H_839567308565656789
+
+    #include <memory>
+    #include <cstddef> //std::byte
+
+
+namespace std
+{
+//https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html
+//https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
+
+#ifndef __cpp_lib_type_trait_variable_templates //GCC 7.1
+    template<class T, class U> constexpr bool is_same_v = is_same<T, U>::value;
+    template<class T> constexpr bool is_const_v  = is_const<T>::value;
+    template<class T> constexpr bool is_signed_v = is_signed<T>::value;
+    template<class T> constexpr bool is_trivially_destructible_v = is_trivially_destructible<T>::value;
+#endif
+
+#if __GNUC__ < 7 || (__GNUC__ == 7 && __GNUC_MINOR__ < 1) //GCC doesn't define __cpp_lib_raw_memory_algorithms
+template<class T> void destroy_at(T* p) { p->~T(); }
+
+template< class ForwardIt >
+void destroy(ForwardIt first, ForwardIt last)
+{
+    for (; first != last; ++first)
+        std::destroy_at(std::addressof(*first));
+}
+
+template<class InputIt, class ForwardIt>
+ForwardIt uninitialized_move(InputIt first, InputIt last, ForwardIt trg_first)
+{
+    typedef typename std::iterator_traits<ForwardIt>::value_type Value;
+    ForwardIt current = trg_first;
+    try
+    {
+        for (; first != last; ++first, ++current)
+            ::new (static_cast<void*>(std::addressof(*current))) Value(std::move(*first));
+        return current;
+    }
+    catch (...)
+    {
+        for (; trg_first != current; ++trg_first)
+            trg_first->~Value();
+        throw;
+    }
+}
+#endif
+
+#ifndef __cpp_lib_apply //GCC 7.1
+template <class F, class T0, class T1, class T2>
+constexpr decltype(auto) apply(F&& f, std::tuple<T0, T1, T2>& t) { return f(std::get<0>(t), std::get<1>(t), std::get<2>(t)); }
+#endif
+
+#if __GNUC__ < 7 || (__GNUC__ == 7 && __GNUC_MINOR__ < 1) //__cpp_lib_byte not defined before GCC 7.3 but supported earlier
+    typedef unsigned char byte;
+#endif
+
+#ifndef __cpp_lib_bool_constant //GCC 6.1
+    template<bool B> using bool_constant = integral_constant<bool, B>;
+#endif
+
+//================================================================================
+
+}
+namespace __cxxabiv1
+{
+struct __cxa_eh_globals;
+extern "C" __cxa_eh_globals* __cxa_get_globals() noexcept;
+}
+namespace std
+{
+inline int uncaught_exceptions_legacy_hack() noexcept
+{
+    return *(reinterpret_cast<unsigned int*>(static_cast<char*>(static_cast<void*>(__cxxabiv1::__cxa_get_globals())) + sizeof(void*)));
+}
+#ifndef __cpp_lib_uncaught_exceptions //GCC 6.1
+inline int uncaught_exceptions() noexcept { return uncaught_exceptions_legacy_hack(); }
+#endif
+
+}
+
+#endif //LEGACY_COMPILER_H_839567308565656789