pub unsafe extern "C" fn switch_channel_set_variable_name_printf(
channel: *mut switch_channel_t,
val: *const c_char,
fmt: *const c_char,
...
) -> switch_status_tpub unsafe extern "C" fn switch_channel_set_variable_name_printf(
channel: *mut switch_channel_t,
val: *const c_char,
fmt: *const c_char,
...
) -> switch_status_t