#[unsafe(no_mangle)]pub unsafe extern "C" fn synthetic_instrument_change_formula(
synth: &mut SyntheticInstrument_API,
formula_ptr: *const c_char,
)#[unsafe(no_mangle)]pub unsafe extern "C" fn synthetic_instrument_change_formula(
synth: &mut SyntheticInstrument_API,
formula_ptr: *const c_char,
)