PRO_DEF_MEM_DISPATCH#define PRO_DEF_MEM_DISPATCH // see below
Macro PRO_DEF_MEM_DISPATCH defines dispatch types for member function expressions with accessibility. It supports two syntaxes:
// (1)
PRO_DEF_MEM_DISPATCH(dispatch_name, func_name);
// (2)
PRO_DEF_MEM_DISPATCH(dispatch_name, func_name, accessibility_func_name);
(1) Equivalent to PRO_DEF_MEM_DISPATCH(dispatch_name, func_name, func_name);
(2) Defines a class named dispatch_name of member function call expressions of func_name with accessibility via member function overloads named accessibility_func_name. Effectively equivalent to:
struct dispatch_name {
template <class T, class... Args>
decltype(auto) operator()(T&& self, Args&&... args) const
noexcept(noexcept(std::forward<T>(self).func_name(std::forward<Args>(args)...)))
requires(requires { std::forward<T>(self).func_name(std::forward<Args>(args)...); }) {
return std::forward<T>(self).func_name(std::forward<Args>(args)...);
}
template <class F, bool IsDirect, class D, class... Os>
struct accessor {
accessor() = delete;
};
template <class F, bool IsDirect, class D, class... Os>
requires(sizeof...(Os) > 1u && (std::is_constructible_v<accessor<F, IsDirect, D, Os>> && ...))
struct accessor<F, IsDirect, D, Os...> : accessor<F, IsDirect, D, Os>... {
using accessor<F, IsDirect, D, Os>::accessibility_func_name ...;
};
template <class F, bool IsDirect, class D, class R, class... Args>
struct accessor<F, IsDirect, D, R(Args...) cv ref noex> {
R accessibility_func_name(Args... args) cv ref noex {
return pro::proxy_invoke<IsDirect, D, R(Args...) cv ref noex>(pro::access_proxy<F>(std::forward<accessor cv ref>(*this)), std::forward<Args>(args)...);
}
};
}
#include <iostream>
#include <string>
#include <vector>
#include "proxy.h"
PRO_DEF_MEM_DISPATCH(MemAt, at);
struct Dictionary : pro::facade_builder
::add_convention<MemAt, std::string(int index) const>
::build {};
int main() {
std::vector<const char*> v{"hello", "world"};
pro::proxy<Dictionary> p = &v;
std::cout << p->at(1) << "\n"; // Prints "world"
}