renamed _check -> check_

(Identifiers starting with underscores are reserved by the standard)
Also fixed a typo in a comment.

include/pybind11/numpy.h

@@ -349,7 +349,7 @@ public:
         int flags = 0;
         if (base && ptr) {
             if (isinstance<array>(base))
-                /* Copy flags from base (except baseship bit) */
+                /* Copy flags from base (except ownership bit) */
                 flags = reinterpret_borrow<array>(base).flags() & ~detail::npy_api::NPY_ARRAY_OWNDATA_;
             else
                 /* Writable by default, easy to downgrade later on if needed */
@@ -639,7 +639,7 @@ public:
         return result;
     }
 
-    static bool _check(handle h) {
+    static bool check_(handle h) {
         const auto &api = detail::npy_api::get();
         return api.PyArray_Check_(h.ptr())
                && api.PyArray_EquivTypes_(detail::array_proxy(h.ptr())->descr, dtype::of<T>().ptr());

include/pybind11/pytypes.h

@@ -282,7 +282,7 @@ template <typename T> T reinterpret_steal(handle h) { return {h, object::stolen}
     `object` or a class which was exposed to Python as ``py::class_<T>``.
 \endrst */
 template <typename T, detail::enable_if_t<std::is_base_of<object, T>::value, int> = 0>
-bool isinstance(handle obj) { return T::_check(obj); }
+bool isinstance(handle obj) { return T::check_(obj); }
 
 template <typename T, detail::enable_if_t<!std::is_base_of<object, T>::value, int> = 0>
 bool isinstance(handle obj) { return detail::isinstance_generic(obj, typeid(T)); }
@@ -572,7 +572,7 @@ NAMESPACE_END(detail)
         Name(handle h, stolen_t) : Parent(h, stolen) { } \
         PYBIND11_DEPRECATED("Use py::isinstance<py::python_type>(obj) instead") \
         bool check() const { return m_ptr != nullptr && (bool) CheckFun(m_ptr); } \
-        static bool _check(handle h) { return h.ptr() != nullptr && CheckFun(h.ptr()); }
+        static bool check_(handle h) { return h.ptr() != nullptr && CheckFun(h.ptr()); }
 
 #define PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun) \
     PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \