5800 system name-value metadata data value.
typedef struct hc_value_ { hc_type_t hcv_type; union { hc_string_t hcv_string; hc_long_t hcv_long; hc_double_t hcv_double; hc_bytearray_t hcv_bytearray; struct tm hcv_tm; struct timespec hcv_timespec; } hcv; } hc_value_t;
This tagged union type can be used to hold a reference to any of the 5800 system data types.