Function gmp_mpfr_sys::mpfr::mpfr_custom_init_set

pub unsafe extern fn mpfr_custom_init_set(x: *mut __mpfr_struct,
                                          kind: c_int,
                                          exp: mpfr_exp_t,
                                          prec: mpfr_prec_t,
                                          significand: *mut c_void)