Function pio_build_dc_opf_preparation 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pio_build_dc_opf_preparation(
    instance: *const PioCalculationInstance,
    units: *const c_char,
    units_len: usize,
    skip_zero_impedance: bool,
    synthesize_unrated_limits: bool,
    correct_angle_difference_bounds: bool,
    error: *mut *mut PioError,
) -> *mut PioDcOpfPreparation

Build the matrix free DC OPF inputs from one typed instance.

Safety

Pointers and handles must satisfy the crate-level safety requirements.