chore: Change numpy dtype from_args call sig to const ref (#3878)

* Change numpy from_args call signature to avoid copy

* Reorder ctors

* Rename arg

* Fix unnecessary move

* Fix clang-tidy and Add a few missing moves to memory_view pytype

Author: Skylion007

include/pybind11/numpy.h

@@ -547,17 +547,19 @@ class dtype : public object {
                     .ptr();
     }
 
-    explicit dtype(const std::string &format) : dtype(from_args(pybind11::str(format))) {}
+    explicit dtype(const pybind11::str &format) : dtype(from_args(format)) {}
 
-    explicit dtype(const char *format) : dtype(from_args(pybind11::str(format))) {}
+    explicit dtype(const std::string &format) : dtype(pybind11::str(format)) {}
+
+    explicit dtype(const char *format) : dtype(pybind11::str(format)) {}
 
     dtype(list names, list formats, list offsets, ssize_t itemsize) {
         dict args;
         args["names"] = std::move(names);
         args["formats"] = std::move(formats);
         args["offsets"] = std::move(offsets);
         args["itemsize"] = pybind11::int_(itemsize);
-        m_ptr = from_args(std::move(args)).release().ptr();
+        m_ptr = from_args(args).release().ptr();
     }
 
     explicit dtype(int typenum)
@@ -568,7 +570,7 @@ class dtype : public object {
     }
 
     /// This is essentially the same as calling numpy.dtype(args) in Python.
-    static dtype from_args(object args) {
+    static dtype from_args(const object &args) {
         PyObject *ptr = nullptr;
         if ((detail::npy_api::get().PyArray_DescrConverter_(args.ptr(), &ptr) == 0) || !ptr) {
             throw error_already_set();

include/pybind11/pytypes.h

@@ -1914,16 +1914,17 @@ class memoryview : public object {
         return memoryview::from_buffer(reinterpret_cast<void *>(ptr),
                                        sizeof(T),
                                        format_descriptor<T>::value,
-                                       shape,
-                                       strides,
+                                       std::move(shape),
+                                       std::move(strides),
                                        readonly);
     }
 
     template <typename T>
     static memoryview from_buffer(const T *ptr,
                                   detail::any_container<ssize_t> shape,
                                   detail::any_container<ssize_t> strides) {
-        return memoryview::from_buffer(const_cast<T *>(ptr), shape, strides, true);
+        return memoryview::from_buffer(
+            const_cast<T *>(ptr), std::move(shape), std::move(strides), true);
     }
 
     /** \rst

tests/test_numpy_dtypes.cpp

@@ -610,5 +610,5 @@ TEST_SUBMODULE(numpy_dtypes, m) {
           []() { PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_); });
 
     // test_str_leak
-    m.def("dtype_wrapper", [](py::object d) { return py::dtype::from_args(std::move(d)); });
+    m.def("dtype_wrapper", [](const py::object &d) { return py::dtype::from_args(d); });
 }