Error in my C++ 11 code

struct CStreamCopyUtilProxy
{
                    template<bool TT, size_t ArrSize>
                    friend struct CStreamCopyUtilContainer;

                private:
                    const CustomResponseStreamWriter m_writeFunc = nullptr;

                    std::vector<char>** m_container = nullptr;

                public:
                    const CustomResponseStreamWriter Claim(std::vector<char>* myBin) const noexcept
                    {
                        if ((*m_container) != nullptr)
                        {
                            return nullptr;
                        }

                        (*m_container) = myBin;

                        return m_writeFunc;
                    }

                    const void Release() const noexcept
                    {
                        (*m_container) = nullptr;
                    }

                private:
                    constexpr CStreamCopyUtilProxy(const CustomResponseStreamWriter writeFunc, std::vector<char>** cont) noexcept : m_writeFunc(writeFunc)
                    {
                        m_container = cont; //getting error here
                    }
};