24/01/03 23:34:38.84 w4EAqTeZ0.net
>>112
とりあえず書いてみたけどどうですかね？
template<std::size_t buf_size>
struct A {
private:
struct base_ {
virtual ~base_() {};
};
template <typename F>
struct derived_ : base_ {
F f_;
derived_(F f) : f_{ std::move(f) } {}
};
base_* p_;
alignas(alignof(std::max_align_t)) uint8_t buf[buf_size]={0};
public:
A() :p_(nullptr) {};
template <typename F>
void assign(F f) {
if (p_ == nullptr) {
p_ = ::new (buf) derived_<F>{std::move(f)};
}
}
//ｺﾋﾟｰｺﾝｽﾄﾗｸﾀ
A(A& src) {
p_ = ::new (buf) decltype(src.*p_); //ここが怪しい
};
};