#ifndef __sigval_t_defined #define __sigval_t_defined #include /* 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 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