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Update akchilov2.cpp #219

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Dec 30, 2023
Merged

Update akchilov2.cpp #219

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5 changes: 2 additions & 3 deletions src/群友提交/第10题/akchilov2.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,6 @@
#include<tuple>

//需要C++20以上
//msvc下可以编译
//这个程序的原理是用std::is_constructible猜测类的成员类型
//然后使用偏移量来访问类的数据成员
namespace my_utilities
Expand Down Expand Up @@ -167,7 +166,7 @@ template<size_t pack_size, class T, class possibilities> class offset_pointer
{
using construct_list = typename make_construct_list<size<T>() - 1, T, possibilities, tl<>>::type;
public:
offset_pointer(T a) noexcept : baseptr(reinterpret_cast<unsigned char*>(&a)) {}
offset_pointer(T* a) noexcept : baseptr(reinterpret_cast<unsigned char*>(a)) {}
template<size_t I> typename select_element<I, construct_list>::type get() const
{
if constexpr (I == 0) {
Expand Down Expand Up @@ -195,7 +194,7 @@ template<class T, class F, size_t ...I> void for_each_member_impl(T&& t, F&& f,
{
//有点上帝视角了，因为已经看到了所有的数据类型
using possible_types = tl<int, std::string, double>;
offset_pointer<alignof(T), T, possible_types> op{ t };
offset_pointer<alignof(T), T, possible_types> op{ &t };
(f(op.template get<I>()), ...);
}

Expand Down