//
// Copyright (c) 2019 Apple, Inc. All rights reserved.
//
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//
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#ifndef XNU_LIBKERN_LIBKERN_CXX_BOUNDED_ARRAY_H
#define XNU_LIBKERN_LIBKERN_CXX_BOUNDED_ARRAY_H
#if !TAPI
#if DRIVERKIT_FRAMEWORK_INCLUDE
#include <DriverKit/bounded_ptr.h>
#else
#include <libkern/c++/bounded_ptr.h>
#endif /* DRIVERKIT_FRAMEWORK_INCLUDE */
#include <stddef.h>
#include <os/base.h>
namespace libkern {
// `bounded_array` is a simple abstraction for a C-style array.
//
// Unlike C-style arrays, however, it ensures that the array is not accessed
// outside of its bounds. Furthermore, the iterators of the `bounded_array`
// are `bounded_ptr`, which track the range they're allowed to access.
//
// TODO:
// - Should we provide deep comparison operators?
// - Document individual methods
template <typename T, size_t N, typename TrappingPolicy>
struct bounded_array {
// DO NOT USE THIS MEMBER DIRECTLY OR WE WILL BREAK YOUR CODE IN THE FUTURE.
// THIS HAS TO BE PUBLIC FOR THIS TYPE TO SUPPORT AGGREGATE-INITIALIZATION.
T data_[N];
using iterator = bounded_ptr<T, TrappingPolicy>;
using const_iterator = bounded_ptr<T const, TrappingPolicy>;
OS_ALWAYS_INLINE iterator
begin() noexcept
{
return iterator(data_, data_, data_ + N);
}
OS_ALWAYS_INLINE const_iterator
begin() const noexcept
{
return const_iterator(data_, data_, data_ + N);
}
iterator
end() noexcept
{
return iterator(data_ + N, data_, data_ + N);
}
const_iterator
end() const noexcept
{
return const_iterator(data_ + N, data_, data_ + N);
}
constexpr size_t
size() const noexcept
{
return N;
}
constexpr size_t
length() const noexcept
{
return N;
}
constexpr T*
data() noexcept
{
return data_;
}
constexpr T const*
data() const noexcept
{
return data_;
}
OS_ALWAYS_INLINE T&
operator[](ptrdiff_t n)
{
return begin()[n];
}
OS_ALWAYS_INLINE T const&
operator[](ptrdiff_t n) const
{
return begin()[n];
}
};
} // end namespace libkern
#endif /* !TAPI */
#endif // !XNU_LIBKERN_LIBKERN_CXX_BOUNDED_ARRAY_H