Class memoryview

include/pybind11/pytypes.h:2393–2509

};

class memoryview : public object {
public:
    PYBIND11_OBJECT_CVT(memoryview, object, PyMemoryView_Check, PyMemoryView_FromObject)

    /** \rst
        Creates ``memoryview`` from ``buffer_info``.

        ``buffer_info`` must be created from ``buffer::request()``. Otherwise
        throws an exception.

        For creating a ``memoryview`` from objects that support buffer protocol,
        use ``memoryview(const object& obj)`` instead of this constructor.
     \endrst */
    explicit memoryview(const buffer_info &info) {
        if (!info.view()) {
            pybind11_fail("Prohibited to create memoryview without Py_buffer");
        }
        // Note: PyMemoryView_FromBuffer never increments obj reference.
        m_ptr = (info.view()->obj) ? PyMemoryView_FromObject(info.view()->obj)
                                   : PyMemoryView_FromBuffer(info.view());
        if (!m_ptr) {
            pybind11_fail("Unable to create memoryview from buffer descriptor");
        }
    }

    /** \rst
        Creates ``memoryview`` from static buffer.

        This method is meant for providing a ``memoryview`` for C/C++ buffer not
        managed by Python. The caller is responsible for managing the lifetime
        of ``ptr`` and ``format``, which MUST outlive the memoryview constructed
        here.

        See also: Python C API documentation for `PyMemoryView_FromBuffer`_.

        .. _PyMemoryView_FromBuffer:
           https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromBuffer

        :param ptr: Pointer to the buffer.
        :param itemsize: Byte size of an element.
        :param format: Pointer to the null-terminated format string. For
            homogeneous Buffers, this should be set to
            ``format_descriptor<T>::value``.
        :param shape: Shape of the tensor (1 entry per dimension).
        :param strides: Number of bytes between adjacent entries (for each
            per dimension).
        :param readonly: Flag to indicate if the underlying storage may be
            written to.
     \endrst */
    static memoryview from_buffer(void *ptr,
                                  ssize_t itemsize,
                                  const char *format,
                                  detail::any_container<ssize_t> shape,
                                  detail::any_container<ssize_t> strides,
                                  bool readonly = false);

    static memoryview from_buffer(const void *ptr,
                                  ssize_t itemsize,