knx/examples/knxPython/pybind11/tests/test_operator_overloading.cpp

/*
    tests/test_operator_overloading.cpp -- operator overloading

    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>

    All rights reserved. Use of this source code is governed by a
    BSD-style license that can be found in the LICENSE file.
*/

#include <pybind11/operators.h>
#include <pybind11/stl.h>

#include "constructor_stats.h"
#include "pybind11_tests.h"

#include <functional>

class Vector2
{
    public:
        Vector2(float x, float y) : x(x), y(y)
        {
            print_created(this, toString());
        }
        Vector2(const Vector2& v) : x(v.x), y(v.y)
        {
            print_copy_created(this);
        }
        Vector2(Vector2&& v) noexcept : x(v.x), y(v.y)
        {
            print_move_created(this);
            v.x = v.y = 0;
        }
        Vector2& operator=(const Vector2& v)
        {
            x = v.x;
            y = v.y;
            print_copy_assigned(this);
            return *this;
        }
        Vector2& operator=(Vector2&& v) noexcept
        {
            x = v.x;
            y = v.y;
            v.x = v.y = 0;
            print_move_assigned(this);
            return *this;
        }
        ~Vector2()
        {
            print_destroyed(this);
        }

        std::string toString() const
        {
            return "[" + std::to_string(x) + ", " + std::to_string(y) + "]";
        }

        Vector2 operator-() const
        {
            return Vector2(-x, -y);
        }
        Vector2 operator+(const Vector2& v) const
        {
            return Vector2(x + v.x, y + v.y);
        }
        Vector2 operator-(const Vector2& v) const
        {
            return Vector2(x - v.x, y - v.y);
        }
        Vector2 operator-(float value) const
        {
            return Vector2(x - value, y - value);
        }
        Vector2 operator+(float value) const
        {
            return Vector2(x + value, y + value);
        }
        Vector2 operator*(float value) const
        {
            return Vector2(x * value, y * value);
        }
        Vector2 operator/(float value) const
        {
            return Vector2(x / value, y / value);
        }
        Vector2 operator*(const Vector2& v) const
        {
            return Vector2(x * v.x, y * v.y);
        }
        Vector2 operator/(const Vector2& v) const
        {
            return Vector2(x / v.x, y / v.y);
        }
        Vector2& operator+=(const Vector2& v)
        {
            x += v.x;
            y += v.y;
            return *this;
        }
        Vector2& operator-=(const Vector2& v)
        {
            x -= v.x;
            y -= v.y;
            return *this;
        }
        Vector2& operator*=(float v)
        {
            x *= v;
            y *= v;
            return *this;
        }
        Vector2& operator/=(float v)
        {
            x /= v;
            y /= v;
            return *this;
        }
        Vector2& operator*=(const Vector2& v)
        {
            x *= v.x;
            y *= v.y;
            return *this;
        }
        Vector2& operator/=(const Vector2& v)
        {
            x /= v.x;
            y /= v.y;
            return *this;
        }

        friend Vector2 operator+(float f, const Vector2& v)
        {
            return Vector2(f + v.x, f + v.y);
        }
        friend Vector2 operator-(float f, const Vector2& v)
        {
            return Vector2(f - v.x, f - v.y);
        }
        friend Vector2 operator*(float f, const Vector2& v)
        {
            return Vector2(f * v.x, f * v.y);
        }
        friend Vector2 operator/(float f, const Vector2& v)
        {
            return Vector2(f / v.x, f / v.y);
        }

        bool operator==(const Vector2& v) const
        {
            return x == v.x && y == v.y;
        }
        bool operator!=(const Vector2& v) const
        {
            return x != v.x || y != v.y;
        }

    private:
        float x, y;
};

class C1 {};
class C2 {};

int operator+(const C1&, const C1&)
{
    return 11;
}
int operator+(const C2&, const C2&)
{
    return 22;
}
int operator+(const C2&, const C1&)
{
    return 21;
}
int operator+(const C1&, const C2&)
{
    return 12;
}

struct HashMe
{
    std::string member;
};

bool operator==(const HashMe& lhs, const HashMe& rhs)
{
    return lhs.member == rhs.member;
}

// Note: Specializing explicit within `namespace std { ... }` is done due to a
// bug in GCC<7. If you are supporting compilers later than this, consider
// specializing `using template<> struct std::hash<...>` in the global
// namespace instead, per this recommendation:
// https://en.cppreference.com/w/cpp/language/extending_std#Adding_template_specializations
namespace std
{
    template <>
    struct hash<Vector2>
    {
        // Not a good hash function, but easy to test
        size_t operator()(const Vector2&)
        {
            return 4;
        }
    };

    // HashMe has a hash function in C++ but no `__hash__` for Python.
    template <>
    struct hash<HashMe>
    {
        std::size_t operator()(const HashMe& selector) const
        {
            return std::hash<std::string>()(selector.member);
        }
    };
} // namespace std

// Not a good abs function, but easy to test.
std::string abs(const Vector2&)
{
    return "abs(Vector2)";
}

// clang 7.0.0 and Apple LLVM 10.0.1 introduce `-Wself-assign-overloaded` to
// `-Wall`, which is used here for overloading (e.g. `py::self += py::self `).
// Here, we suppress the warning
// Taken from: https://github.com/RobotLocomotion/drake/commit/aaf84b46
// TODO(eric): This could be resolved using a function / functor (e.g. `py::self()`).
#if defined(__APPLE__) && defined(__clang__)
    #if (__clang_major__ >= 10)
        PYBIND11_WARNING_DISABLE_CLANG("-Wself-assign-overloaded")
    #endif
#elif defined(__clang__)
    #if (__clang_major__ >= 7)
        PYBIND11_WARNING_DISABLE_CLANG("-Wself-assign-overloaded")
    #endif
#endif

TEST_SUBMODULE(operators, m)
{

    // test_operator_overloading
    py::class_<Vector2>(m, "Vector2")
    .def(py::init<float, float>())
    .def(py::self + py::self)
    .def(py::self + float())
    .def(py::self - py::self)
    .def(py::self - float())
    .def(py::self * float())
    .def(py::self / float())
    .def(py::self * py::self)
    .def(py::self / py::self)
    .def(py::self += py::self)
    .def(py::self -= py::self)
    .def(py::self *= float())
    .def(py::self /= float())
    .def(py::self *= py::self)
    .def(py::self /= py::self)
    .def(float() + py::self)
    .def(float() - py::self)
    .def(float() * py::self)
    .def(float() / py::self)
    .def(-py::self)
    .def("__str__", &Vector2::toString)
    .def("__repr__", &Vector2::toString)
    .def(py::self == py::self)
    .def(py::self != py::self)
    .def(py::hash(py::self))
    // N.B. See warning about usage of `py::detail::abs(py::self)` in
    // `operators.h`.
    .def("__abs__", [](const Vector2 & v)
    {
        return abs(v);
    });

    m.attr("Vector") = m.attr("Vector2");

    // test_operators_notimplemented
    // #393: need to return NotSupported to ensure correct arithmetic operator behavior
    py::class_<C1>(m, "C1").def(py::init<>()).def(py::self + py::self);

    py::class_<C2>(m, "C2")
    .def(py::init<>())
    .def(py::self + py::self)
    .def("__add__", [](const C2 & c2, const C1 & c1)
    {
        return c2 + c1;
    })
    .def("__radd__", [](const C2 & c2, const C1 & c1)
    {
        return c1 + c2;
    });

    // test_nested
    // #328: first member in a class can't be used in operators
    struct NestABase
    {
        int value = -2;
    };
    py::class_<NestABase>(m, "NestABase")
    .def(py::init<>())
    .def_readwrite("value", &NestABase::value);

    struct NestA : NestABase
    {
        int value = 3;
        NestA& operator+=(int i)
        {
            value += i;
            return *this;
        }
    };
    py::class_<NestA>(m, "NestA")
    .def(py::init<>())
    .def(py::self += int())
    .def(
        "as_base",
        [](NestA & a) -> NestABase & { return (NestABase&) a; },
        py::return_value_policy::reference_internal);
    m.def("get_NestA", [](const NestA & a)
    {
        return a.value;
    });

    struct NestB
    {
        NestA a;
        int value = 4;
        NestB& operator-=(int i)
        {
            value -= i;
            return *this;
        }
    };
    py::class_<NestB>(m, "NestB")
    .def(py::init<>())
    .def(py::self -= int())
    .def_readwrite("a", &NestB::a);
    m.def("get_NestB", [](const NestB & b)
    {
        return b.value;
    });

    struct NestC
    {
        NestB b;
        int value = 5;
        NestC& operator*=(int i)
        {
            value *= i;
            return *this;
        }
    };
    py::class_<NestC>(m, "NestC")
    .def(py::init<>())
    .def(py::self *= int())
    .def_readwrite("b", &NestC::b);
    m.def("get_NestC", [](const NestC & c)
    {
        return c.value;
    });

    // test_overriding_eq_reset_hash
    // #2191 Overriding __eq__ should set __hash__ to None
    struct Comparable
    {
        int value;
        bool operator==(const Comparable& rhs) const
        {
            return value == rhs.value;
        }
    };

    struct Hashable : Comparable
    {
        explicit Hashable(int value) : Comparable{value} {};
        size_t hash() const
        {
            return static_cast<size_t>(value);
        }
    };

    struct Hashable2 : Hashable
    {
        using Hashable::Hashable;
    };

    py::class_<Comparable>(m, "Comparable").def(py::init<int>()).def(py::self == py::self);

    py::class_<Hashable>(m, "Hashable")
    .def(py::init<int>())
    .def(py::self == py::self)
    .def("__hash__", &Hashable::hash);

    // define __hash__ before __eq__
    py::class_<Hashable2>(m, "Hashable2")
    .def("__hash__", &Hashable::hash)
    .def(py::init<int>())
    .def(py::self == py::self);

    // define __eq__ but not __hash__
    py::class_<HashMe>(m, "HashMe").def(py::self == py::self);

    m.def("get_unhashable_HashMe_set", []()
    {
        return std::unordered_set<HashMe> {{"one"}};
    });
}