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#ifndef EXACT_REF_COUNTED_CAST_INL_H_
#error "Direct inclusion of this file is not allowed, include exact_ref_counted_cast.h"
// For the sake of sane code completion.
#include "exact_ref_counted_cast.h"
#endif
#include "new.h"
#include <typeinfo>
namespace NYT {
////////////////////////////////////////////////////////////////////////////////
template <class T, class U>
std::conditional_t<std::is_const_v<U>, const T, T>* ExactRefCountedCast(U* ptr) noexcept
{
static_assert(std::is_polymorphic_v<U>,
"ExactRefCountedCast requires a polymorphic operand type");
static_assert(std::is_base_of_v<TRefCountedBase, T>,
"ExactRefCountedCast target must derive from TRefCountedBase");
static_assert(std::is_final_v<TRefCountedWrapper<T>>,
"TRefCountedWrapper must stay final for this cast to remain O(1)");
using TWrapper = std::conditional_t<std::is_const_v<U>, const TRefCountedWrapper<T>, TRefCountedWrapper<T>>;
// Wrapper is final, so dynamic_cast lowers to one type_info compare.
return dynamic_cast<TWrapper*>(ptr);
}
template <class T, class U>
std::conditional_t<std::is_const_v<U>, const T, T>& ExactRefCountedCast(U& ref)
{
static_assert(std::is_polymorphic_v<U>,
"ExactRefCountedCast requires a polymorphic operand type");
static_assert(std::is_base_of_v<TRefCountedBase, T>,
"ExactRefCountedCast target must derive from TRefCountedBase");
static_assert(std::is_final_v<TRefCountedWrapper<T>>,
"TRefCountedWrapper must stay final for this cast to remain O(1)");
using TWrapper = std::conditional_t<std::is_const_v<U>, const TRefCountedWrapper<T>, TRefCountedWrapper<T>>;
return dynamic_cast<TWrapper&>(ref);
}
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT
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