56 lines
1.0 KiB
C++
56 lines
1.0 KiB
C++
#pragma once
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template <class T>
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class CowPtr
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{
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public:
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typedef std::shared_ptr<T> RefPtr;
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private:
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mutable RefPtr m_sp;
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void detach()
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{
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if( !( m_sp == nullptr || m_sp.unique() ) ) {
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m_sp = std::make_shared<T>(*m_sp);
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}
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}
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public:
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CowPtr() = default;
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CowPtr(const RefPtr& refptr)
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: m_sp(refptr)
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{
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}
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bool operator==(std::nullptr_t) const
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{
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return m_sp == nullptr;
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}
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bool operator!=(std::nullptr_t) const
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{
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return m_sp != nullptr;
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}
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const T& operator*() const
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{
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return *m_sp;
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}
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T& operator*()
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{
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detach();
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return *m_sp;
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}
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const T* operator->() const
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{
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return m_sp.operator->();
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}
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T* operator->()
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{
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detach();
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return m_sp.operator->();
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}
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};
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