Function ion_c_sys::ion_writer_write_field_name_symbol

pub unsafe extern "C" fn ion_writer_write_field_name_symbol(
    hwriter: hWRITER, 
    field_name: *mut ION_SYMBOL
) -> iERR

Sets the writer’s current field name from the given Ion symbol. Only valid if the writer is currently in a struct. It is the caller’s responsibility to keep field_name in scope until the writer’s next value is written.