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Merge branch 'master' of github.com:TartanLlama/expected

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This commit is contained in:
Simon Brand
2018-05-28 21:48:14 +01:00
parent 4a8b2e51b2 12334cb13b
commit 36e08034f6
3 changed files with 230 additions and 20 deletions
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2
README.md
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@@ -88,7 +88,7 @@ Requires [Catch](https://github.com/philsquared/Catch) for testing. This is bund
### Acknowledgements
Thanks to [Kévin Alexandre Boissonneault](https://github.com/KABoissonneault) for various bug fixes.
Thanks to [Kévin Alexandre Boissonneault](https://github.com/KABoissonneault) and [Björn Fahller](https://github.com/rollbear) for various bug fixes.
----------

189
tests/extensions.cpp
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@@ -368,6 +368,195 @@ TEST_CASE("And then extensions", "[extensions.and_then]") {
}
}
TEST_CASE("or_else", "[extensions.or_else]") {
using eptr = std::unique_ptr<int>;
auto succeed = [](int a) { return tl::expected<int, int>(21 * 2); };
auto succeedptr = [](eptr e) { return tl::expected<int,eptr>(21*2);};
auto fail = [](int a) { return tl::expected<int,int>(tl::unexpect, 17);};
auto efail = [](eptr e) { *e = 17;return tl::expected<int,eptr>(tl::unexpect, std::move(e));};
auto failptr = [](eptr e) { return tl::expected<int,eptr>(tl::unexpect, std::move(e));};
auto failvoid = [](int) {};
auto failvoidptr = [](const eptr&) { /* don't consume */};
auto consumeptr = [](eptr) {};
auto make_u_int = [](int n) { return std::unique_ptr<int>(new int(n));};
{
tl::expected<int, int> e = 21;
auto ret = e.or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
const tl::expected<int, int> e = 21;
auto ret = e.or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
tl::expected<int, int> e = 21;
auto ret = std::move(e).or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
tl::expected<int, eptr> e = 21;
auto ret = std::move(e).or_else(succeedptr);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
const tl::expected<int, int> e = 21;
auto ret = std::move(e).or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
tl::expected<int, int> e = 21;
auto ret = e.or_else(fail);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
const tl::expected<int, int> e = 21;
auto ret = e.or_else(fail);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
tl::expected<int, int> e = 21;
auto ret = std::move(e).or_else(fail);
REQUIRE(ret);
REQUIRE(ret == 21);
}
{
tl::expected<int, eptr> e = 21;
auto ret = std::move(e).or_else(efail);
REQUIRE(ret);
REQUIRE(ret == 21);
}
{
const tl::expected<int, int> e = 21;
auto ret = std::move(e).or_else(fail);
REQUIRE(ret);
REQUIRE(*ret == 21);
}
{
tl::expected<int, int> e(tl::unexpect, 21);
auto ret = e.or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 42);
}
{
const tl::expected<int, int> e(tl::unexpect, 21);
auto ret = e.or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 42);
}
{
tl::expected<int, int> e(tl::unexpect, 21);
auto ret = std::move(e).or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 42);
}
{
tl::expected<int, eptr> e(tl::unexpect, make_u_int(21));
auto ret = std::move(e).or_else(succeedptr);
REQUIRE(ret);
REQUIRE(*ret == 42);
}
{
const tl::expected<int, int> e(tl::unexpect, 21);
auto ret = std::move(e).or_else(succeed);
REQUIRE(ret);
REQUIRE(*ret == 42);
}
{
tl::expected<int, int> e(tl::unexpect, 21);
auto ret = e.or_else(fail);
REQUIRE(!ret);
REQUIRE(ret.error() == 17);
}
{
tl::expected<int, int> e(tl::unexpect, 21);
auto ret = e.or_else(failvoid);
REQUIRE(!ret);
REQUIRE(ret.error() == 21);
}
{
const tl::expected<int, int> e(tl::unexpect, 21);
auto ret = e.or_else(fail);
REQUIRE(!ret);
REQUIRE(ret.error() == 17);
}
{
const tl::expected<int, int> e(tl::unexpect, 21);
auto ret = e.or_else(failvoid);
REQUIRE(!ret);
REQUIRE(ret.error() == 21);
}
{
tl::expected<int, int> e(tl::unexpect, 21);
auto ret = std::move(e).or_else(fail);
REQUIRE(!ret);
REQUIRE(ret.error() == 17);
}
{
tl::expected<int, int> e(tl::unexpect, 21);
auto ret = std::move(e).or_else(failvoid);
REQUIRE(!ret);
REQUIRE(ret.error() == 21);
}
{
tl::expected<int, eptr> e(tl::unexpect, make_u_int(21));
auto ret = std::move(e).or_else(failvoidptr);
REQUIRE(!ret);
REQUIRE(*ret.error() == 21);
}
{
tl::expected<int, eptr> e(tl::unexpect, make_u_int(21));
auto ret = std::move(e).or_else(consumeptr);
REQUIRE(!ret);
REQUIRE(ret.error() == nullptr);
}
{
const tl::expected<int, int> e(tl::unexpect, 21);
auto ret = std::move(e).or_else(fail);
REQUIRE(!ret);
REQUIRE(ret.error() == 17);
}
{
const tl::expected<int, int> e(tl::unexpect, 21);
auto ret = std::move(e).or_else(failvoid);
REQUIRE(!ret);
REQUIRE(ret.error() == 21);
}
}
struct S {
int x;
};

59
tl/expected.hpp
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@@ -1369,11 +1369,11 @@ public:
#endif
/// \brief Calls `f` if the expectd is in the unexpected state
/// \requires `std::invoke_result_t<F>` must be void or convertible to
/// `expcted<T,E>`.
/// \requires `F` is invokable with `E`, and `std::invoke_result_t<F>`
/// must be void or convertible to `expcted<T,E>`.
/// \effects If `*this` has a value, returns `*this`.
/// Otherwise, if `f` returns `void`, calls `std::forward<F>(f)` and returns
/// `std::nullopt`. Otherwise, returns `std::forward<F>(f)()`.
/// Otherwise, if `f` returns `void`, calls `std::forward<F>(f)(E)` and returns
/// `std::nullopt`. Otherwise, returns `std::forward<F>(f)(E)`.
///
/// \group or_else
template <class F> expected TL_EXPECTED_11_CONSTEXPR or_else(F &&f) & {
@@ -1388,10 +1388,11 @@ public:
return or_else_impl(*this, std::forward<F>(f));
}
#ifndef TL_EXPECTED_NO_CONSTRR
template <class F> expected constexpr or_else(F &&f) const && {
return or_else_impl(std::move(*this), std::forward<F>(f));
}
#endif
constexpr expected() = default;
constexpr expected(const expected &rhs) = default;
constexpr expected(expected &&rhs) = default;
@@ -2009,31 +2010,51 @@ auto map_error_impl(Exp &&exp, F &&f) -> expected<exp_t<Exp>, monostate> {
}
#endif
#ifdef TL_EXPECTED_CXX14
template <class Exp, class F,
class Ret = decltype(detail::invoke(std::declval<F>(),
*std::declval<Exp>())),
std::declval<Exp>().error())),
detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
constexpr detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) {
if (exp.has_value()) {
return std::forward<Exp>(exp);
}
return detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp));
constexpr auto or_else_impl(Exp &&exp, F &&f) {
static_assert(detail::is_expected<Ret>::value, "F must return an expected");
return exp.has_value()
? std::forward<Exp>(exp)
: detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
}
template <class Exp, class F,
class Ret = decltype(detail::invoke(std::declval<F>(),
*std::declval<Exp>())),
std::declval<Exp>().error())),
detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) {
if (exp.has_value()) {
return std::forward<Exp>(exp);
}
detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp));
return std::forward<Exp>(exp);
return exp.has_value()
? std::forward<Exp>(exp)
: (detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()),
std::forward<Exp>(exp));
}
#else
template <class Exp, class F,
class Ret = decltype(detail::invoke(std::declval<F>(),
std::declval<Exp>().error())),
detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
auto or_else_impl(Exp &&exp, F &&f) -> Ret {
static_assert(detail::is_expected<Ret>::value, "F must return an expected");
return exp.has_value()
? std::forward<Exp>(exp)
: detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
}
template <class Exp, class F,
class Ret = decltype(detail::invoke(std::declval<F>(),
std::declval<Exp>().error())),
detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) {
return exp.has_value()
? std::forward<Exp>(exp)
: (detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()),
std::forward<Exp>(exp));
}
#endif
} // namespace detail
template <class T, class E, class U, class F>