pub unsafe extern "C" fn jl_call2(
f: *mut jl_function_t,
a: *mut jl_value_t,
b: *mut jl_value_t
) -> *mut jl_value_t
pub unsafe extern "C" fn jl_call2(
f: *mut jl_function_t,
a: *mut jl_value_t,
b: *mut jl_value_t
) -> *mut jl_value_t