From 80db2383d8a8b7af3576eecb821b941848900574 Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Mon, 30 Jul 2018 16:00:47 +0200
Subject: [PATCH] Speculative va_copy() fix for old versions of GCC/Clang.
 (cannot repro) (#1085)

---
 imgui.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/imgui.cpp b/imgui.cpp
index 426d1964..9b998bd1 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -1931,8 +1931,12 @@ bool ImGuiTextFilter::PassFilter(const char* text, const char* text_end) const
 // On some platform vsnprintf() takes va_list by reference and modifies it.
 // va_copy is the 'correct' way to copy a va_list but Visual Studio prior to 2013 doesn't have it.
 #ifndef va_copy
+#if defined(__GNUC__) || defined(__clang__)
+#define va_copy(dest, src) __builtin_va_copy(dest, src)
+#else
 #define va_copy(dest, src) (dest = src)
 #endif
+#endif
 
 // Helper: Text buffer for logging/accumulating text
 void ImGuiTextBuffer::appendfv(const char* fmt, va_list args)