Created
April 5, 2022 22:29
-
-
Save ecatmur/eb6590bcd53d4ec0c082d03153950c45 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <type_traits> | |
template<class, auto, auto, auto> | |
class accessor; | |
template<class C, auto id, auto getter, auto setter> | |
class property : public decltype( | |
id.template operator()<accessor<C, id, getter, setter>>())::type {}; | |
template<class C, auto id, auto getter, auto setter> | |
class accessor { | |
private: | |
using P = property<C, id, getter, setter>; | |
C& self() { return *static_cast<C*>(reinterpret_cast<P*>(this)); } | |
C const& self() const { return *static_cast<C const*>(reinterpret_cast<P const*>(this)); } | |
public: | |
decltype(auto) get() { return getter(self()); } | |
decltype(auto) get() const { return getter(self()); } | |
operator decltype(auto)() { return get(); } | |
operator decltype(auto)() const { return get(); } | |
decltype(auto) operator=(auto value) { return setter(self(), value); } | |
}; | |
#define ID(id) []<class T> { struct B { T id; }; return std::type_identity<B>(); } | |
#define PROPERTY(C, id, getter, setter) \ | |
property<C, ID(id), getter, setter> | |
#include <chrono> | |
#include <string> | |
class Person : | |
public PROPERTY(Person, name, | |
[](auto const& self) { return self.mName; }, | |
[](auto& self, auto name) { self.mName = name; }), | |
public PROPERTY(Person, age, | |
[](auto const& self) { return self.mAge; }, | |
[](auto& self, auto age) { self.mAge = age; }) | |
{ | |
private: | |
std::string mName; | |
std::chrono::years mAge; | |
}; | |
#include <iostream> | |
int main() { | |
Person p; | |
p.name = "Fred"; | |
p.age = std::chrono::years(22); | |
std::cout << "Happy " << p.age.get() << " birthday, " << p.name.get() << "!" << std::endl; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment