text: #ifndef __sigval_t_defined
  #define __sigval_t_defined
  
  #include <bits/types/__sigval_t.h>
  
  /* To avoid sigval_t (not a standard type name) having C++ name
     mangling depending on whether the selected standard includes union
     sigval, it should not be defined at all when using a standard for
     which the sigval name is not reserved; in that case, headers should
     not include <bits/types/sigval_t.h> and should use only the
     internal __sigval_t name.  */
  #ifndef __USE_POSIX199309
  # error "sigval_t defined for standard not including union sigval"
  #endif
  
  typedef __sigval_t sigval_t;
  
  #endif