gettimeofday: port recent C++ fix to Emacs

[gnulib.git] / m4 / cbrtf.m4

diff --git a/m4/cbrtf.m4 b/m4/cbrtf.m4
index f948bd4..5c3c0f9 100644 (file)
--- a/m4/cbrtf.m4
+++ b/m4/cbrtf.m4
@@ -1,5 +1,5 @@
-# cbrtf.m4 serial 2
-dnl Copyright (C) 2012 Free Software Foundation, Inc.
+# cbrtf.m4 serial 3
+dnl Copyright (C) 2012-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -9,6 +9,9 @@ AC_DEFUN([gl_FUNC_CBRTF],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_CBRT])
 
+  dnl Persuade glibc <math.h> to declare cbrtf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether cbrtf() exists. Assume that cbrtf(), if it exists, is
   dnl defined in the same library as cbrt().
   save_LIBS="$LIBS"