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Merged
Bronek merged 1 commit into from
Feb 18, 2026
Merged

Improve support for move only types #175

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34 changes: 17 additions & 17 deletions include/pfn/expected.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -275,39 +275,39 @@ template <class T, class E> class expected {
rhs.set_ = true;
}

constexpr T const &_value() const &
constexpr T const &_value() const & noexcept
{
ASSERT(set_);
return v_;
}
constexpr T &_value() &
constexpr T &_value() & noexcept
{
ASSERT(set_);
return v_;
}
constexpr T const &&_value() const &&
constexpr T const &&_value() const && noexcept
{
ASSERT(set_);
return ::std::move(v_);
}
constexpr T &&_value() &&
constexpr T &&_value() && noexcept
{
ASSERT(set_);
return ::std::move(v_);
}

template <typename Self, typename Fn>
static constexpr auto _and_then(Self &&self, Fn &&fn) //
noexcept(::std::is_nothrow_invocable_v<Fn, decltype(FWD(self).value())>
noexcept(::std::is_nothrow_invocable_v<Fn, decltype(FWD(self)._value())>
&& ::std::is_nothrow_constructible_v<E, decltype(FWD(self).error())>)
requires(::std::is_invocable_v<Fn, decltype(FWD(self).value())>
requires(::std::is_invocable_v<Fn, decltype(FWD(self)._value())>
&& ::std::is_constructible_v<E, decltype(FWD(self).error())>)
{
using result_t = ::std::remove_cvref_t<::std::invoke_result_t<Fn, decltype(FWD(self).value())>>;
using result_t = ::std::remove_cvref_t<::std::invoke_result_t<Fn, decltype(FWD(self)._value())>>;
static_assert(detail::_is_some_expected<result_t>);
static_assert(::std::is_same_v<typename result_t::error_type, typename ::std::remove_cvref_t<Self>::error_type>);
if (self.has_value()) {
return ::std::invoke(FWD(fn), FWD(self).value());
return ::std::invoke(FWD(fn), FWD(self)._value());
}
return result_t(unexpect, FWD(self).error());
}
Expand All @@ -330,24 +330,24 @@ template <class T, class E> class expected {

template <typename Self, typename Fn>
static constexpr auto _transform(Self &&self, Fn &&fn) //
noexcept(::std::is_nothrow_invocable_v<Fn, decltype(FWD(self).value())>
noexcept(::std::is_nothrow_invocable_v<Fn, decltype(FWD(self)._value())>
&& ::std::is_nothrow_constructible_v<E, decltype(FWD(self).error())>
&& (::std::is_void_v<::std::invoke_result_t<Fn, decltype(FWD(self).value())>>
&& (::std::is_void_v<::std::invoke_result_t<Fn, decltype(FWD(self)._value())>>
|| ::std::is_nothrow_constructible_v<
::std::remove_cv_t<::std::invoke_result_t<Fn, decltype(FWD(self).value())>>,
::std::invoke_result_t<Fn, decltype(FWD(self).value())>>))
requires(::std::is_invocable_v<Fn, decltype(FWD(self).value())>
::std::remove_cv_t<::std::invoke_result_t<Fn, decltype(FWD(self)._value())>>,
::std::invoke_result_t<Fn, decltype(FWD(self)._value())>>))
requires(::std::is_invocable_v<Fn, decltype(FWD(self)._value())>
&& ::std::is_constructible_v<E, decltype(FWD(self).error())>)
{
using value_t = ::std::remove_cv_t<::std::invoke_result_t<Fn, decltype(FWD(self).value())>>;
using value_t = ::std::remove_cv_t<::std::invoke_result_t<Fn, decltype(FWD(self)._value())>>;
static_assert(detail::_is_valid_expected<value_t, E>);
using result_t = expected<value_t, E>;
if (self.has_value()) {
if constexpr (not ::std::is_void_v<value_t>) {
static_assert(::std::is_constructible_v<value_t, ::std::invoke_result_t<Fn, decltype(FWD(self).value())>>);
return result_t(::std::in_place, ::std::invoke(FWD(fn), FWD(self).value()));
static_assert(::std::is_constructible_v<value_t, ::std::invoke_result_t<Fn, decltype(FWD(self)._value())>>);
return result_t(::std::in_place, ::std::invoke(FWD(fn), FWD(self)._value()));
} else {
::std::invoke(FWD(fn), FWD(self).value());
::std::invoke(FWD(fn), FWD(self)._value());
return result_t(::std::in_place);
}
}
Expand Down