gentoo-overlay/dev-db/postgis/files/postgis-3.0.3-detect-only-stdc.patch

diff -Naruw postgis-3.1.0.orig/configure.ac postgis-3.1.0/configure.ac
--- postgis-3.1.0.orig/configure.ac	2020-12-18 14:39:26.000000000 -0500
+++ postgis-3.1.0/configure.ac	2020-12-19 07:35:13.232167083 -0500
@@ -1501,12 +1501,9 @@
             dnl ============================================================
             CC="$WAGYU_CXX"
 
-            AC_CHECK_LIB(c++, main, [HAVE_CPP=yes], [HAVE_CPP=no])
             AC_CHECK_LIB(stdc++, main, [HAVE_STDCPP=yes], [HAVE_STDCPP=no])
 
-            if test "x$HAVE_CPP" = "xyes"; then
-                WAGYU_LDFLAGS="-lc++"
-            elif test "x$HAVE_STDCPP" = "xyes"; then
+            if test "x$HAVE_STDCPP" = "xyes"; then
                 WAGYU_LDFLAGS="-lstdc++"
             else
                 AC_MSG_WARN("Could not find a C++ standard library")