Add explicit casts to avoid compiler warnings (#1294)

Author: hpkfft

include/nanobind/nb_func.h

@@ -195,7 +195,7 @@ NB_INLINE PyObject *func_create(Func &&func, Return (*)(Args...),
     // Pre-initialize argument flags with 'convert'. The 'accepts_none' flag
     // for std::optional<> args is applied after func_extra_apply (see below).
     if constexpr (has_arg_defaults) {
-        ((void)(Is < is_method_det ||
+        ((void)(Is < (size_t)is_method_det ||
                 (f.args[Is - is_method_det] = { nullptr, nullptr, nullptr, nullptr,
                     (uint8_t) cast_flags::convert }, true)), ...);
     } else if constexpr (nargs_provided > 0) {
@@ -328,7 +328,7 @@ NB_INLINE PyObject *func_create(Func &&func, Return (*)(Args...),
     // Apply implicit accepts_none for std::optional<> typed arguments
     // after func_extra_apply, so that explicit nb::arg().noconvert() works.
     if constexpr (has_arg_defaults) {
-        ((void)(Is >= is_method_det && has_arg_defaults_v<Args> &&
+        ((void)(Is >= (size_t)is_method_det && has_arg_defaults_v<Args> &&
                 (f.args[Is - is_method_det].flag |=
                      (uint8_t) cast_flags::accepts_none, true)), ...);
     }

src/nb_ndarray.cpp

@@ -271,7 +271,7 @@ static PyObject *nb_ndarray_dlpack(PyObject *self, PyObject *const *args,
 
     ndarray_handle *th = ((nb_ndarray *) self)->th;
     PyObject *capsule;
-    if (max_major_version >= dlpack::major_version)
+    if (max_major_version >= (long)dlpack::major_version)
         capsule = th->make_capsule_versioned();
     else
         capsule = th->make_capsule_unversioned();