pub unsafe extern "C" fn vmmin(
n: c_int,
b: *mut c_double,
Fmin: *mut c_double,
_fn: optimfn,
gr: optimgr,
maxit: c_int,
trace: c_int,
mask: *mut c_int,
abstol: c_double,
reltol: c_double,
nREPORT: c_int,
ex: *mut c_void,
fncount: *mut c_int,
grcount: *mut c_int,
fail: *mut c_int,
)