m4/nansignal.m4

   1 AC_DEFUN([AC_CHECK_NANSIGNAL],
   2 [
   3         AC_MSG_CHECKING([whether doubles signal NaN])
   4         AC_LANG_PUSH(C++)
   5         AC_RUN_IFELSE([AC_LANG_SOURCE([
   6 #include <limits>
   7 #include <cstdlib>
   8
   9 int main()
  10 {
  11         exit(!std::numeric_limits<double>::has_signaling_NaN);
  12 }
  13 ])], [AC_MSG_RESULT(yes)],
  14          [
  15                 AC_MSG_RESULT(no)
  16                 AC_MSG_ERROR([cannot compile Shapes without NaN signals, aborting!])
  17          ],
  18          [AC_MSG_RESULT(maybe)])
  19
  20         AC_LANG_POP(C++)
  21 ])
  22
  23