From b787a57bf24ccd47380a97ee7b0468f095363273 Mon Sep 17 00:00:00 2001
From: halx99 <halx99@live.com>
Date: Sun, 6 Jun 2021 16:15:26 +0800
Subject: [PATCH] Improve astc cmake for ios

---
 external/astc/CMakeLists.txt | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/external/astc/CMakeLists.txt b/external/astc/CMakeLists.txt
index ca87a61807..e28cb816a9 100644
--- a/external/astc/CMakeLists.txt
+++ b/external/astc/CMakeLists.txt
@@ -71,13 +71,10 @@ if (NOT DEFINED ISA_SIMD)
                 }" ASTC_HAVE_SSE4_INTRINSICS)
     endif()
 
-    ### restore CMAKE_REQUIRED_FLAGS
-    set(CMAKE_REQUIRED_FLAGS ${OLD_REQUIRED_FLAGS})
-    unset(OLD_REQUIRED_FLAGS)
-
     ### check neon
     check_include_file(arm_neon.h ASTC_HAVE_ARM_NEON_H)
     if(ASTC_HAVE_ARM_NEON_H)
+        set(CMAKE_REQUIRED_FLAGS "-std=c++11")
         check_cxx_source_compiles("#include <arm_neon.h>
                 int main()
                 {
@@ -88,6 +85,10 @@ if (NOT DEFINED ISA_SIMD)
                 }" ASTC_HAVE_NEON_INTRINSICS)
     endif()
 
+    ### restore CMAKE_REQUIRED_FLAGS
+    set(CMAKE_REQUIRED_FLAGS ${OLD_REQUIRED_FLAGS})
+    unset(OLD_REQUIRED_FLAGS)    
+
     ### set ISA_SIMD
     if(ASTC_HAVE_MSSE2_SWITCH)
         set(ISA_SIMD "sse2")