Replace std::mem_fn with custom lambda in ranges

This commit is contained in:
Maxime Coste 2019-01-24 21:09:07 +11:00
parent 3e89148d74
commit b91367f8a3

View File

@ -5,7 +5,6 @@
#include <utility>
#include <iterator>
#include <numeric>
#include <functional>
#include "constexpr_utils.hh"
@ -191,10 +190,31 @@ inline auto transform(Transform t)
});
}
template<typename T, typename U, typename = void>
struct is_pointer_like : std::false_type {};
template<typename T, typename U>
struct is_pointer_like<T, U, std::enable_if_t<std::is_same_v<std::decay_t<decltype(*std::declval<U>())>, std::decay_t<T>>>> : std::true_type {};
template<typename M, typename T>
inline auto transform(M T::*m)
inline auto transform(M T::*member)
{
return transform(std::mem_fn(std::forward<decltype(m)>(m)));
return transform([member](auto&& arg) -> decltype(auto) {
using Arg = decltype(arg);
using Member = decltype(member);
auto get_object = [&] () mutable -> decltype(auto) {
if constexpr (is_pointer_like<T, Arg>::value)
return *std::forward<Arg>(arg);
else
return std::forward<Arg>(arg);
};
if constexpr (std::is_member_function_pointer_v<Member>)
return (get_object().*member)();
else
return get_object().*member;
});
}
template<typename Range, bool escape, bool include_separator,