Source of /tests/intrusive_shared_ptr_src/cast.static.cpp (From xnu-11215.1.10)

//
// Tests for
//  template<typename To, typename From, typename R>
//  intrusive_shared_ptr<To, R> static_pointer_cast(intrusive_shared_ptr<From, R> const& ptr) noexcept;
//
//  template<typename To, typename From, typename R>
//  intrusive_shared_ptr<To, R> static_pointer_cast(intrusive_shared_ptr<From, R>&& ptr) noexcept
//

#include <libkern/c++/intrusive_shared_ptr.h>
#include <utility>
#include <darwintest.h>
#include "test_policy.h"

struct Base { int i; };
struct Derived : Base { };

struct Base1 { int i; };
struct Base2 { long l; };
struct DerivedMultiple : Base1, Base2 {
	DerivedMultiple(int i) : Base1{i}, Base2{i + 10}
	{
	}
};

template <typename Stored, typename From, typename To>
static void
tests()
{
	Stored obj{3};

	{
		tracked_shared_ptr<From> const from(&obj, libkern::no_retain);
		tracking_policy::reset();
		tracked_shared_ptr<To> to = libkern::static_pointer_cast<To>(from);
		CHECK(tracking_policy::retains == 1);
		CHECK(tracking_policy::releases == 0);
		CHECK(to.get() == static_cast<To const*>(&obj));
		CHECK(from.get() == &obj);
	}
	{
		tracked_shared_ptr<From> from(&obj, libkern::no_retain);
		tracking_policy::reset();
		tracked_shared_ptr<To> to = libkern::static_pointer_cast<To>(std::move(from));
		CHECK(tracking_policy::retains == 0);
		CHECK(tracking_policy::releases == 0);
		CHECK(to.get() == static_cast<To const*>(&obj));
		CHECK(from.get() == nullptr);
	}

	// Test `static_pointer_cast`ing a null pointer
	{
		tracked_shared_ptr<From> const from = nullptr;
		tracking_policy::reset();
		tracked_shared_ptr<To> to = libkern::static_pointer_cast<To>(from);
		CHECK(tracking_policy::retains == 0);
		CHECK(tracking_policy::releases == 0);
		CHECK(to.get() == nullptr);
		CHECK(from.get() == nullptr);
	}
	{
		tracked_shared_ptr<From> from = nullptr;
		tracking_policy::reset();
		tracked_shared_ptr<To> to = libkern::static_pointer_cast<To>(std::move(from));
		CHECK(tracking_policy::retains == 0);
		CHECK(tracking_policy::releases == 0);
		CHECK(to.get() == nullptr);
		CHECK(from.get() == nullptr);
	}
}

T_DECL(cast_static, "intrusive_shared_ptr.cast.static", T_META_TAG_VM_PREFERRED) {
	tests</*stored*/ Derived, /*from*/ Derived, /*to*/ Base>();
	tests</*stored*/ Derived, /*from*/ Derived const, /*to*/ Base const>();

	tests</*stored*/ DerivedMultiple, /*from*/ DerivedMultiple, /*to*/ Base1>();
	tests</*stored*/ DerivedMultiple, /*from*/ DerivedMultiple const, /*to*/ Base1 const>();
}