From ff3a6a1c2888eab92679dd330641978e7e6feb5d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sl=C3=A1vek=20Banko?= <slavek.banko@axis.cz>
Date: Wed, 30 Oct 2019 19:30:37 +0100
Subject: Add check whether OpenEXR requires explicit specification of C++
 standard.
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Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 82895daec0ccb16c14b98e1b21b49dd71d68dd2f)
---
 configure.in.in | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

(limited to 'configure.in.in')

diff --git a/configure.in.in b/configure.in.in
index 01eed782..fcc96492 100644
--- a/configure.in.in
+++ b/configure.in.in
@@ -288,6 +288,37 @@ fi
 if test -n "$OPENEXR_LIBS"
 then
   AC_MSG_RESULT([yes])
+
+  AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  SAVED_CXXFLAGS="$CXXFLAGS"
+  for CXX_STD_TEST in "" 11 14 17; do
+    CXXFLAGS="$SAVED_CXXFLAGS"
+    if test "x$CXX_STD_TEST" = "x"; then
+      AC_MSG_CHECKING([OpenEXR build with default C++ standard])
+      OPENEXR_CXXFLAGS=""
+    else
+      AC_MSG_CHECKING([OpenEXR build with C++$CXX_STD_TEST])
+      OPENEXR_CXXFLAGS="-std=c++$CXX_STD_TEST"
+    fi
+    CXXFLAGS="$SAVED_CXXFLAGS $OPENEXR_CFLAGS $OPENEXR_CXXFLAGS"
+    AC_TRY_COMPILE([
+        #include <ImfRgbaFile.h>
+      ],[ ],
+      openexr_cxx_std=yes,
+      openexr_cxx_std=no
+    )
+    if test "x$openexr_cxx_std" = "xyes"; then
+      AC_SUBST(OPENEXR_CXXFLAGS)
+      AC_MSG_RESULT(yes)
+      break
+    else
+      AC_MSG_RESULT(no)
+    fi
+  done
+  CXXFLAGS="$SAVED_CXXFLAGS"
+  AC_LANG_RESTORE
+
 else
   AC_MSG_RESULT([not found])
 fi
@@ -296,6 +327,6 @@ AC_SUBST(OPENEXR_LIBS)
 AC_SUBST(OPENEXR_CFLAGS)
 AC_SUBST(OPENEXR_RPATH)
 
-AM_CONDITIONAL(have_openexr, test -n "$OPENEXR_LIBS")
+AM_CONDITIONAL(have_openexr, test "x$openexr_cxx_std" = "xyes")
 
 # --- End of OpenEXR check ---
-- 
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