我试图将文字传递给完美的转发设置器，但这会导致对象构造，移动和破坏。我正在寻找一种更有效的方法。

struct TStruct {
    TStruct(int va) : a(va) {
        std::cout << "- TStruct(" << va << ")" << std::endl;
    }
    TStruct(const TStruct& other) :
        a(other.a)
    {
        std::cout << "- TStruct(const TStruct& )" << std::endl;
    }
    TStruct(TStruct&& other) :
        a(std::exchange(other.a,0))
    {
        std::cout << "- TStruct(const TStruct&&)" << std::endl;
    }
    TStruct& operator=(const TStruct& rhs) {
        std::cout << "- TStruct operator= const& " << std::endl;
        // check for self-assignment
        if(&rhs == this) return *this;
        a = rhs.a;
        return *this;
    }
    TStruct& operator=(TStruct&& rhs) {
        std::cout << "- TStruct operator=&&" << std::endl;
        // check for self-assignment
        if(&rhs == this) return *this;
        a = std::exchange(rhs.a,0);
        return *this;
    }
    ~TStruct() {
        std::cout << "~ TStruct() destructor with " << a << std::endl;
    }
    int a = 1;
};

struct TPerfectForward {
    template<class T>
    TPerfectForward(T&& tsv) : ts(std::forward<T>(tsv)) {}

    template<class T>
    void set(T&& tsv) { ts = std::forward<T>(tsv); }

    TStruct ts;
};

std::cout << "TPerfectForward (5)" << std::endl;
TPerfectForward pf(5);

std::cout << "TPerfectForward set(4)" << std::endl;
pf.set(4);

在Ubuntu上使用gcc 7.4.0可获得以下结果：

TPerfectForward (5);
- TStruct(5)
TPerfectForward set(4)
- TStruct(4)
- TStruct operator=&&
~ TStruct() destructor with 0

我希望这些结果更好：

TPerfectForward (5)
- TStruct(5)
TPerfectForward set(4)
- TStruct(4)

当完美转发到函数时，是否有一种方法可以避免调用move运算符和析构函数？