PRO_DEF_FREE_DISPATCH#define PRO_DEF_FREE_DISPATCH // see below
Macro PRO_DEF_FREE_DISPATCH defines dispatch types for free function expressions with accessibility. It supports two syntaxes:
// (1)
PRO_DEF_FREE_DISPATCH(dispatch_name, func_name);
// (2)
PRO_DEF_FREE_DISPATCH(dispatch_name, func_name, accessibility_func_name);
(1) Equivalent to PRO_DEF_FREE_DISPATCH(dispatch_name, func_name, func_name);
(2) Defines a class named dispatch_name of free function call expressions of func_name with accessibility via free 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(func_name(std::forward<T>(self), std::forward<Args>(args)...)))
requires(requires { func_name(std::forward<T>(self), std::forward<Args>(args)...); }) {
return func_name(std::forward<T>(self), 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>... {};
template <class F, bool IsDirect, class D, class R, class... Args>
struct accessor<F, IsDirect, D, R(Args...) cv ref noex> {
friend R accessibility_func_name(accessor_arg cv ref self, Args... args) noex {
return pro::proxy_invoke<IsDirect, D, R(Args...) cv ref noex>(pro::access_proxy<F>(std::forward<accessor_arg cv ref>(self)), std::forward<Args>(args)...);
}
};
}
#include <iostream>
#include <string>
#include "proxy.h"
PRO_DEF_FREE_DISPATCH(FreeToString, std::to_string, ToString);
struct Stringable : pro::facade_builder
::add_convention<FreeToString, std::string()>
::build {};
int main() {
pro::proxy<Stringable> p = pro::make_proxy<Stringable>(123);
std::cout << ToString(*p) << "\n"; // Prints "123"
}