Function vips_sys::im__colour_unary

pub unsafe extern "C" fn im__colour_unary(
    domain: *const c_char, 
    in_: *mut VipsImage, 
    out: *mut VipsImage, 
    interpretation: VipsInterpretation, 
    buffer_fn: im_wrapone_fn, 
    a: *mut c_void, 
    b: *mut c_void
) -> c_int