69 lines
2.6 KiB
C++
69 lines
2.6 KiB
C++
// #########################################################################
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// PLEASE UPDATE docs/advanced/cast/custom.rst IF ANY CHANGES ARE MADE HERE.
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// #########################################################################
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#include "pybind11_tests.h"
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namespace user_space {
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struct Point2D {
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double x;
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double y;
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};
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Point2D negate(const Point2D &point) { return Point2D{-point.x, -point.y}; }
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} // namespace user_space
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namespace pybind11 {
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namespace detail {
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template <>
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struct type_caster<user_space::Point2D> {
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// This macro inserts a lot of boilerplate code and sets the type hint.
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// `io_name` is used to specify different type hints for arguments and return values.
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// The signature of our negate function would then look like:
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// `negate(Sequence[float]) -> tuple[float, float]`
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PYBIND11_TYPE_CASTER(user_space::Point2D, io_name("Sequence[float]", "tuple[float, float]"));
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// C++ -> Python: convert `Point2D` to `tuple[float, float]`. The second and third arguments
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// are used to indicate the return value policy and parent object (for
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// return_value_policy::reference_internal) and are often ignored by custom casters.
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// The return value should reflect the type hint specified by the second argument of `io_name`.
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static handle
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cast(const user_space::Point2D &number, return_value_policy /*policy*/, handle /*parent*/) {
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return py::make_tuple(number.x, number.y).release();
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}
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// Python -> C++: convert a `PyObject` into a `Point2D` and return false upon failure. The
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// second argument indicates whether implicit conversions should be allowed.
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// The accepted types should reflect the type hint specified by the first argument of
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// `io_name`.
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bool load(handle src, bool /*convert*/) {
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// Check if handle is a Sequence
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if (!py::isinstance<py::sequence>(src)) {
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return false;
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}
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auto seq = py::reinterpret_borrow<py::sequence>(src);
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// Check if exactly two values are in the Sequence
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if (seq.size() != 2) {
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return false;
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}
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// Check if each element is either a float or an int
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for (auto item : seq) {
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if (!py::isinstance<py::float_>(item) && !py::isinstance<py::int_>(item)) {
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return false;
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}
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}
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value.x = seq[0].cast<double>();
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value.y = seq[1].cast<double>();
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return true;
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}
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};
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} // namespace detail
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} // namespace pybind11
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// Bind the negate function
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TEST_SUBMODULE(docs_advanced_cast_custom, m) { m.def("negate", user_space::negate); }
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