Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
#include <stdint.h>
#include <string.h>
#include "mozilla/ResultVariant.h"
#include "mozilla/Try.h"
#include "mozilla/UniquePtr.h"
using mozilla::Err;
using mozilla::GenericErrorResult;
using mozilla::Ok;
using mozilla::Result;
using mozilla::UniquePtr;
#define MOZ_STATIC_AND_RELEASE_ASSERT(expr) \
static_assert(expr); \
MOZ_RELEASE_ASSERT(expr)
enum struct TestUnusedZeroEnum : int16_t { Ok = 0, NotOk = 1 };
namespace mozilla::detail {
template <>
struct UnusedZero<TestUnusedZeroEnum> : UnusedZeroEnum<TestUnusedZeroEnum> {};
} // namespace mozilla::detail
struct Failed {};
namespace mozilla::detail {
template <>
struct UnusedZero<Failed> {
using StorageType = uintptr_t;
static constexpr bool value = true;
static constexpr StorageType nullValue = 0;
static constexpr StorageType GetDefaultValue() { return 2; }
static constexpr void AssertValid(StorageType aValue) {}
static constexpr Failed Inspect(const StorageType& aValue) {
return Failed{};
}
static constexpr Failed Unwrap(StorageType aValue) { return Failed{}; }
static constexpr StorageType Store(Failed aValue) {
return GetDefaultValue();
}
};
} // namespace mozilla::detail
// V is trivially default-constructible, and E has UnusedZero<E>::value == true,
// for a reference type and for a non-reference type
static_assert(mozilla::detail::SelectResultImpl<uintptr_t, Failed>::value ==
mozilla::detail::PackingStrategy::NullIsOk);
static_assert(
mozilla::detail::SelectResultImpl<Ok, TestUnusedZeroEnum>::value ==
mozilla::detail::PackingStrategy::NullIsOk);
static_assert(mozilla::detail::SelectResultImpl<Ok, Failed>::value ==
mozilla::detail::PackingStrategy::LowBitTagIsError);
static_assert(std::is_trivially_destructible_v<Result<uintptr_t, Failed>>);
static_assert(std::is_trivially_destructible_v<Result<Ok, TestUnusedZeroEnum>>);
static_assert(std::is_trivially_destructible_v<Result<Ok, Failed>>);
static_assert(
sizeof(Result<bool, TestUnusedZeroEnum>) <= sizeof(uintptr_t),
"Result with bool value type should not be larger than pointer-sized");
static_assert(sizeof(Result<Ok, Failed>) == sizeof(uint8_t),
"Result with empty value type should be size 1");
static_assert(sizeof(Result<int*, Failed>) == sizeof(uintptr_t),
"Result with two aligned pointer types should be pointer-sized");
static_assert(
sizeof(Result<char*, Failed*>) > sizeof(char*),
"Result with unaligned success type `char*` must not be pointer-sized");
static_assert(
sizeof(Result<int*, char*>) > sizeof(char*),
"Result with unaligned error type `char*` must not be pointer-sized");
enum Foo8 : uint8_t {};
enum Foo16 : uint16_t {};
enum Foo32 : uint32_t {};
static_assert(sizeof(Result<Ok, Foo8>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
static_assert(sizeof(Result<Ok, Foo16>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
static_assert(sizeof(Foo32) >= sizeof(uintptr_t) ||
sizeof(Result<Ok, Foo32>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
static_assert(sizeof(Result<Foo16, Foo8>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
static_assert(sizeof(Result<Foo8, Foo16>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
static_assert(sizeof(Foo32) >= sizeof(uintptr_t) ||
sizeof(Result<Foo32, Foo16>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
static_assert(sizeof(Foo32) >= sizeof(uintptr_t) ||
sizeof(Result<Foo16, Foo32>) <= sizeof(uintptr_t),
"Result with small types should be pointer-sized");
#if __cplusplus < 202002L
static_assert(std::is_literal_type_v<Result<int*, Failed>>);
static_assert(std::is_literal_type_v<Result<Ok, Failed>>);
static_assert(std::is_literal_type_v<Result<Ok, Foo8>>);
static_assert(std::is_literal_type_v<Result<Foo8, Foo16>>);
static_assert(!std::is_literal_type_v<Result<Ok, UniquePtr<int>>>);
#endif
static constexpr GenericErrorResult<Failed> Fail() { return Err(Failed{}); }
static constexpr GenericErrorResult<TestUnusedZeroEnum>
FailTestUnusedZeroEnum() {
return Err(TestUnusedZeroEnum::NotOk);
}
static constexpr Result<Ok, Failed> Task1(bool pass) {
if (!pass) {
return Fail(); // implicit conversion from GenericErrorResult to Result
}
return Ok();
}
static constexpr Result<Ok, TestUnusedZeroEnum> Task1UnusedZeroEnumErr(
bool pass) {
if (!pass) {
return FailTestUnusedZeroEnum(); // implicit conversion from
// GenericErrorResult to Result
}
return Ok();
}
static constexpr Result<int, Failed> Task2(bool pass, int value) {
MOZ_TRY(
Task1(pass)); // converts one type of result to another in the error case
return value; // implicit conversion from T to Result<T, E>
}
static constexpr Result<int, TestUnusedZeroEnum> Task2UnusedZeroEnumErr(
bool pass, int value) {
MOZ_TRY(Task1UnusedZeroEnumErr(
pass)); // converts one type of result to another in the error case
return value; // implicit conversion from T to Result<T, E>
}
static Result<int, Failed> Task3(bool pass1, bool pass2, int value) {
int x, y;
MOZ_TRY_VAR(x, Task2(pass1, value));
MOZ_TRY_VAR(y, Task2(pass2, value));
return x + y;
}
static void BasicTests() {
MOZ_STATIC_AND_RELEASE_ASSERT(Task1(true).isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(!Task1(true).isErr());
MOZ_STATIC_AND_RELEASE_ASSERT(!Task1(false).isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(Task1(false).isErr());
MOZ_STATIC_AND_RELEASE_ASSERT(Task1UnusedZeroEnumErr(true).isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(!Task1UnusedZeroEnumErr(true).isErr());
MOZ_STATIC_AND_RELEASE_ASSERT(!Task1UnusedZeroEnumErr(false).isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(Task1UnusedZeroEnumErr(false).isErr());
MOZ_STATIC_AND_RELEASE_ASSERT(TestUnusedZeroEnum::NotOk ==
Task1UnusedZeroEnumErr(false).inspectErr());
MOZ_STATIC_AND_RELEASE_ASSERT(TestUnusedZeroEnum::NotOk ==
Task1UnusedZeroEnumErr(false).unwrapErr());
// MOZ_TRY works.
MOZ_STATIC_AND_RELEASE_ASSERT(Task2(true, 3).isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(Task2(true, 3).unwrap() == 3);
MOZ_STATIC_AND_RELEASE_ASSERT(Task2(true, 3).unwrapOr(6) == 3);
MOZ_RELEASE_ASSERT(Task2(false, 3).isErr());
MOZ_RELEASE_ASSERT(Task2(false, 3).unwrapOr(6) == 6);
MOZ_STATIC_AND_RELEASE_ASSERT(Task2UnusedZeroEnumErr(true, 3).isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(Task2UnusedZeroEnumErr(true, 3).unwrap() == 3);
MOZ_STATIC_AND_RELEASE_ASSERT(Task2UnusedZeroEnumErr(true, 3).unwrapOr(6) ==
3);
MOZ_STATIC_AND_RELEASE_ASSERT(Task2UnusedZeroEnumErr(false, 3).isErr());
MOZ_STATIC_AND_RELEASE_ASSERT(Task2UnusedZeroEnumErr(false, 3).unwrapOr(6) ==
6);
// MOZ_TRY_VAR works.
MOZ_RELEASE_ASSERT(Task3(true, true, 3).isOk());
MOZ_RELEASE_ASSERT(Task3(true, true, 3).unwrap() == 6);
MOZ_RELEASE_ASSERT(Task3(true, false, 3).isErr());
MOZ_RELEASE_ASSERT(Task3(false, true, 3).isErr());
MOZ_RELEASE_ASSERT(Task3(false, true, 3).unwrapOr(6) == 6);
// Lvalues should work too.
{
constexpr Result<Ok, Failed> res1 = Task1(true);
MOZ_STATIC_AND_RELEASE_ASSERT(res1.isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(!res1.isErr());
constexpr Result<Ok, Failed> res2 = Task1(false);
MOZ_STATIC_AND_RELEASE_ASSERT(!res2.isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(res2.isErr());
}
{
Result<int, Failed> res = Task2(true, 3);
MOZ_RELEASE_ASSERT(res.isOk());
MOZ_RELEASE_ASSERT(res.unwrap() == 3);
res = Task2(false, 4);
MOZ_RELEASE_ASSERT(res.isErr());
}
// Some tests for pointer tagging.
{
int i = 123;
Result<int*, Failed> res = &i;
static_assert(sizeof(res) == sizeof(uintptr_t),
"should use pointer tagging to fit in a word");
MOZ_RELEASE_ASSERT(res.isOk());
MOZ_RELEASE_ASSERT(*res.unwrap() == 123);
res = Err(Failed());
MOZ_RELEASE_ASSERT(res.isErr());
}
}
struct NonCopyableNonMovable {
explicit constexpr NonCopyableNonMovable(uint32_t aValue) : mValue(aValue) {}
NonCopyableNonMovable(const NonCopyableNonMovable&) = delete;
NonCopyableNonMovable(NonCopyableNonMovable&&) = delete;
NonCopyableNonMovable& operator=(const NonCopyableNonMovable&) = delete;
NonCopyableNonMovable& operator=(NonCopyableNonMovable&&) = delete;
uint32_t mValue;
};
static void InPlaceConstructionTests() {
{
// PackingStrategy == NullIsOk
static_assert(mozilla::detail::SelectResultImpl<NonCopyableNonMovable,
Failed>::value ==
mozilla::detail::PackingStrategy::NullIsOk);
constexpr Result<NonCopyableNonMovable, Failed> result{std::in_place, 42u};
MOZ_STATIC_AND_RELEASE_ASSERT(42 == result.inspect().mValue);
}
{
// PackingStrategy == Variant
static_assert(
mozilla::detail::SelectResultImpl<NonCopyableNonMovable, int>::value ==
mozilla::detail::PackingStrategy::Variant);
const Result<NonCopyableNonMovable, int> result{std::in_place, 42};
MOZ_RELEASE_ASSERT(42 == result.inspect().mValue);
}
}
/* * */
struct Snafu : Failed {};
static Result<Ok, Snafu*> Explode() {
static Snafu snafu;
return Err(&snafu);
}
static Result<Ok, Failed*> ErrorGeneralization() {
MOZ_TRY(Explode()); // change error type from Snafu* to more general Failed*
return Ok();
}
static void TypeConversionTests() {
MOZ_RELEASE_ASSERT(ErrorGeneralization().isErr());
{
const Result<Ok, Failed*> res = Explode();
MOZ_RELEASE_ASSERT(res.isErr());
}
{
const Result<Ok, Failed*> res = Result<Ok, Snafu*>{Ok{}};
MOZ_RELEASE_ASSERT(res.isOk());
}
}
static void EmptyValueTest() {
struct Fine {};
mozilla::Result<Fine, Failed> res((Fine()));
res.unwrap();
MOZ_RELEASE_ASSERT(res.isOk());
static_assert(sizeof(res) == sizeof(uint8_t),
"Result with empty value and error types should be size 1");
}
static void MapTest() {
struct MyError {
int x;
explicit MyError(int y) : x(y) {}
};
// Mapping over success values, to the same success type.
{
Result<int, MyError> res(5);
bool invoked = false;
auto res2 = res.map([&invoked](int x) {
MOZ_RELEASE_ASSERT(x == 5);
invoked = true;
return 6;
});
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrap() == 6);
}
// Mapping over success values, to a different success type.
{
Result<int, MyError> res(5);
bool invoked = false;
auto res2 = res.map([&invoked](int x) {
MOZ_RELEASE_ASSERT(x == 5);
invoked = true;
return "hello";
});
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(strcmp(res2.unwrap(), "hello") == 0);
}
// Mapping over success values (constexpr).
{
constexpr uint64_t kValue = 42u;
constexpr auto res2a = Result<int32_t, Failed>{5}.map([](int32_t x) {
MOZ_RELEASE_ASSERT(x == 5);
return kValue;
});
MOZ_STATIC_AND_RELEASE_ASSERT(res2a.isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(kValue == res2a.inspect());
}
// Mapping over error values.
{
MyError err(1);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
Result<char, MyError> res2 = res.map([](int x) {
MOZ_RELEASE_ASSERT(false);
return 'a';
});
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(res2.unwrapErr().x == err.x);
}
// Function pointers instead of lambdas as the mapping function.
{
Result<const char*, MyError> res("hello");
auto res2 = res.map(strlen);
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(res2.unwrap() == 5);
}
}
static void MapErrTest() {
struct MyError {
int x;
explicit MyError(int y) : x(y) {}
};
struct MyError2 {
int a;
explicit MyError2(int b) : a(b) {}
};
// Mapping over error values, to the same error type.
{
MyError err(1);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
bool invoked = false;
auto res2 = res.mapErr([&invoked](const auto err) {
MOZ_RELEASE_ASSERT(err.x == 1);
invoked = true;
return MyError(2);
});
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrapErr().x == 2);
}
// Mapping over error values, to a different error type.
{
MyError err(1);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
bool invoked = false;
auto res2 = res.mapErr([&invoked](const auto err) {
MOZ_RELEASE_ASSERT(err.x == 1);
invoked = true;
return MyError2(2);
});
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrapErr().a == 2);
}
// Mapping over success values.
{
Result<int, MyError> res(5);
auto res2 = res.mapErr([](const auto err) {
MOZ_RELEASE_ASSERT(false);
return MyError(1);
});
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(res2.unwrap() == 5);
}
// Function pointers instead of lambdas as the mapping function.
{
Result<Ok, const char*> res("hello");
auto res2 = res.mapErr(strlen);
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(res2.unwrapErr() == 5);
}
}
static Result<Ok, size_t> strlen_ResultWrapper(const char* aValue) {
return Err(strlen(aValue));
}
static void OrElseTest() {
struct MyError {
int x;
explicit constexpr MyError(int y) : x(y) {}
};
struct MyError2 {
int a;
explicit constexpr MyError2(int b) : a(b) {}
};
// `orElse`ing over error values, to Result<V, E> (the same error type) error
// variant.
{
MyError err(1);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
bool invoked = false;
auto res2 = res.orElse([&invoked](const auto err) -> Result<char, MyError> {
MOZ_RELEASE_ASSERT(err.x == 1);
invoked = true;
if (err.x != 42) {
return Err(MyError(2));
}
return 'a';
});
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrapErr().x == 2);
}
// `orElse`ing over error values, to Result<V, E> (the same error type)
// success variant.
{
MyError err(42);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
bool invoked = false;
auto res2 = res.orElse([&invoked](const auto err) -> Result<char, MyError> {
MOZ_RELEASE_ASSERT(err.x == 42);
invoked = true;
if (err.x != 42) {
return Err(MyError(2));
}
return 'a';
});
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrap() == 'a');
}
// `orElse`ing over error values, to Result<V, E2> (a different error type)
// error variant.
{
MyError err(1);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
bool invoked = false;
auto res2 =
res.orElse([&invoked](const auto err) -> Result<char, MyError2> {
MOZ_RELEASE_ASSERT(err.x == 1);
invoked = true;
if (err.x != 42) {
return Err(MyError2(2));
}
return 'a';
});
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrapErr().a == 2);
}
// `orElse`ing over error values, to Result<V, E2> (a different error type)
// success variant.
{
MyError err(42);
Result<char, MyError> res(err);
MOZ_RELEASE_ASSERT(res.isErr());
bool invoked = false;
auto res2 =
res.orElse([&invoked](const auto err) -> Result<char, MyError2> {
MOZ_RELEASE_ASSERT(err.x == 42);
invoked = true;
if (err.x != 42) {
return Err(MyError2(2));
}
return 'a';
});
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(invoked);
MOZ_RELEASE_ASSERT(res2.unwrap() == 'a');
}
// `orElse`ing over success values.
{
Result<int, MyError> res(5);
auto res2 = res.orElse([](const auto err) -> Result<int, MyError> {
MOZ_RELEASE_ASSERT(false);
return Err(MyError(1));
});
MOZ_RELEASE_ASSERT(res2.isOk());
MOZ_RELEASE_ASSERT(res2.unwrap() == 5);
}
// Function pointers instead of lambdas as the `orElse`ing function.
{
Result<Ok, const char*> res("hello");
auto res2 = res.orElse(strlen_ResultWrapper);
MOZ_RELEASE_ASSERT(res2.isErr());
MOZ_RELEASE_ASSERT(res2.unwrapErr() == 5);
}
}
static void AndThenTest() {
// `andThen`ing over success results.
{
Result<int, const char*> r1(10);
Result<int, const char*> r2 =
r1.andThen([](int x) { return Result<int, const char*>(x + 1); });
MOZ_RELEASE_ASSERT(r2.isOk());
MOZ_RELEASE_ASSERT(r2.unwrap() == 11);
}
// `andThen`ing over success results (constexpr).
{
constexpr Result<int, Failed> r2a = Result<int, Failed>{10}.andThen(
[](int x) { return Result<int, Failed>(x + 1); });
MOZ_STATIC_AND_RELEASE_ASSERT(r2a.isOk());
MOZ_STATIC_AND_RELEASE_ASSERT(r2a.inspect() == 11);
}
// `andThen`ing over error results.
{
Result<int, const char*> r3("error");
Result<int, const char*> r4 = r3.andThen([](int x) {
MOZ_RELEASE_ASSERT(false);
return Result<int, const char*>(1);
});
MOZ_RELEASE_ASSERT(r4.isErr());
MOZ_RELEASE_ASSERT(r3.unwrapErr() == r4.unwrapErr());
}
// andThen with a function accepting an rvalue
{
Result<int, const char*> r1(10);
Result<int, const char*> r2 =
r1.andThen([](int&& x) { return Result<int, const char*>(x + 1); });
MOZ_RELEASE_ASSERT(r2.isOk());
MOZ_RELEASE_ASSERT(r2.unwrap() == 11);
}
// `andThen`ing over error results (constexpr).
{
constexpr Result<int, Failed> r4a =
Result<int, Failed>{Failed{}}.andThen([](int x) {
MOZ_RELEASE_ASSERT(false);
return Result<int, Failed>(1);
});
MOZ_STATIC_AND_RELEASE_ASSERT(r4a.isErr());
}
}
using UniqueResult = Result<UniquePtr<int>, const char*>;
static UniqueResult UniqueTask() { return mozilla::MakeUnique<int>(3); }
static UniqueResult UniqueTaskError() { return Err("bad"); }
using UniqueErrorResult = Result<int, UniquePtr<int>>;
static UniqueErrorResult UniqueError() {
return Err(mozilla::MakeUnique<int>(4));
}
static Result<Ok, UniquePtr<int>> TryUniqueErrorResult() {
MOZ_TRY(UniqueError());
return Ok();
}
static void UniquePtrTest() {
{
auto result = UniqueTask();
MOZ_RELEASE_ASSERT(result.isOk());
auto ptr = result.unwrap();
MOZ_RELEASE_ASSERT(ptr);
MOZ_RELEASE_ASSERT(*ptr == 3);
auto moved = result.unwrap();
MOZ_RELEASE_ASSERT(!moved);
}
{
auto err = UniqueTaskError();
MOZ_RELEASE_ASSERT(err.isErr());
auto ptr = err.unwrapOr(mozilla::MakeUnique<int>(4));
MOZ_RELEASE_ASSERT(ptr);
MOZ_RELEASE_ASSERT(*ptr == 4);
}
{
auto result = UniqueTaskError();
result = UniqueResult(mozilla::MakeUnique<int>(6));
MOZ_RELEASE_ASSERT(result.isOk());
MOZ_RELEASE_ASSERT(result.inspect() && *result.inspect() == 6);
}
{
auto result = UniqueError();
MOZ_RELEASE_ASSERT(result.isErr());
MOZ_RELEASE_ASSERT(result.inspectErr());
MOZ_RELEASE_ASSERT(*result.inspectErr() == 4);
auto err = result.unwrapErr();
MOZ_RELEASE_ASSERT(!result.inspectErr());
MOZ_RELEASE_ASSERT(err);
MOZ_RELEASE_ASSERT(*err == 4);
result = UniqueErrorResult(0);
MOZ_RELEASE_ASSERT(result.isOk() && result.unwrap() == 0);
}
{
auto result = TryUniqueErrorResult();
MOZ_RELEASE_ASSERT(result.isErr());
auto err = result.unwrapErr();
MOZ_RELEASE_ASSERT(err && *err == 4);
MOZ_RELEASE_ASSERT(!result.inspectErr());
}
}
struct ZeroIsUnusedStructForPointer {
int x = 1;
};
enum class ZeroIsUnusedEnum1 : uint8_t {
V1 = 1,
V2 = 2,
};
enum class ZeroIsUnusedEnum2 : uint16_t {
V1 = 1,
V2 = 2,
};
enum class ZeroIsUnusedEnum4 : uint32_t {
V1 = 1,
V2 = 2,
};
enum class ZeroIsUnusedEnum8 : uint64_t {
V1 = 1,
V2 = 2,
};
struct EmptyErrorStruct {};
template <>
struct mozilla::detail::UnusedZero<ZeroIsUnusedStructForPointer*> {
static const bool value = true;
};
template <>
struct mozilla::detail::UnusedZero<ZeroIsUnusedEnum1> {
static const bool value = true;
};
template <>
struct mozilla::detail::UnusedZero<ZeroIsUnusedEnum2> {
static const bool value = true;
};
template <>
struct mozilla::detail::UnusedZero<ZeroIsUnusedEnum4> {
static const bool value = true;
};
template <>
struct mozilla::detail::UnusedZero<ZeroIsUnusedEnum8> {
static const bool value = true;
};
static void ZeroIsEmptyErrorTest() {
{
ZeroIsUnusedStructForPointer s;
using V = ZeroIsUnusedStructForPointer*;
mozilla::Result<V, EmptyErrorStruct> result(&s);
MOZ_RELEASE_ASSERT(sizeof(result) == sizeof(V));
MOZ_RELEASE_ASSERT(result.isOk());
MOZ_RELEASE_ASSERT(result.inspect() == &s);
}
{
using V = ZeroIsUnusedStructForPointer*;
mozilla::Result<V, EmptyErrorStruct> result(Err(EmptyErrorStruct{}));
MOZ_RELEASE_ASSERT(result.isErr());
MOZ_RELEASE_ASSERT(*reinterpret_cast<V*>(&result) == nullptr);
}
{
ZeroIsUnusedEnum1 e = ZeroIsUnusedEnum1::V1;
using V = ZeroIsUnusedEnum1;
mozilla::Result<V, EmptyErrorStruct> result(e);
MOZ_RELEASE_ASSERT(sizeof(result) == sizeof(V));
MOZ_RELEASE_ASSERT(result.isOk());
MOZ_RELEASE_ASSERT(result.inspect() == e);
}
{
using V = ZeroIsUnusedEnum1;
mozilla::Result<V, EmptyErrorStruct> result(Err(EmptyErrorStruct()));
MOZ_RELEASE_ASSERT(result.isErr());
MOZ_RELEASE_ASSERT(*reinterpret_cast<uint8_t*>(&result) == 0);
}
{
ZeroIsUnusedEnum2 e = ZeroIsUnusedEnum2::V1;
using V = ZeroIsUnusedEnum2;
mozilla::Result<V, EmptyErrorStruct> result(e);
MOZ_RELEASE_ASSERT(sizeof(result) == sizeof(V));
MOZ_RELEASE_ASSERT(result.isOk());
MOZ_RELEASE_ASSERT(result.inspect() == e);
}
{
using V = ZeroIsUnusedEnum2;
mozilla::Result<V, EmptyErrorStruct> result(Err(EmptyErrorStruct()));
MOZ_RELEASE_ASSERT(result.isErr());
MOZ_RELEASE_ASSERT(*reinterpret_cast<uint16_t*>(&result) == 0);
}
{
ZeroIsUnusedEnum4 e = ZeroIsUnusedEnum4::V1;
using V = ZeroIsUnusedEnum4;
mozilla::Result<V, EmptyErrorStruct> result(e);
MOZ_RELEASE_ASSERT(sizeof(result) == sizeof(V));
MOZ_RELEASE_ASSERT(result.isOk());
MOZ_RELEASE_ASSERT(result.inspect() == e);
}
{
using V = ZeroIsUnusedEnum4;
mozilla::Result<V, EmptyErrorStruct> result(Err(EmptyErrorStruct()));
MOZ_RELEASE_ASSERT(result.isErr());
MOZ_RELEASE_ASSERT(*reinterpret_cast<uint32_t*>(&result) == 0);
}
{
ZeroIsUnusedEnum8 e = ZeroIsUnusedEnum8::V1;
using V = ZeroIsUnusedEnum8;
mozilla::Result<V, EmptyErrorStruct> result(e);
MOZ_RELEASE_ASSERT(sizeof(result) == sizeof(V));
MOZ_RELEASE_ASSERT(result.isOk());
MOZ_RELEASE_ASSERT(result.inspect() == e);
}
{
using V = ZeroIsUnusedEnum8;
mozilla::Result<V, EmptyErrorStruct> result(Err(EmptyErrorStruct()));
MOZ_RELEASE_ASSERT(result.isErr());
MOZ_RELEASE_ASSERT(*reinterpret_cast<uint64_t*>(&result) == 0);
}
}
class Foo {};
class C1 {};
class C2 : public C1 {};
class E1 {};
class E2 : public E1 {};
void UpcastTest() {
{
C2 c2;
mozilla::Result<C2*, Failed> result(&c2);
mozilla::Result<C1*, Failed> copied(std::move(result));
MOZ_RELEASE_ASSERT(copied.inspect() == &c2);
}
{
E2 e2;
mozilla::Result<Foo, E2*> result(Err(&e2));
mozilla::Result<Foo, E1*> copied(std::move(result));
MOZ_RELEASE_ASSERT(copied.inspectErr() == &e2);
}
{
C2 c2;
mozilla::Result<C2*, E2*> result(&c2);
mozilla::Result<C1*, E1*> copied(std::move(result));
MOZ_RELEASE_ASSERT(copied.inspect() == &c2);
}
{
E2 e2;
mozilla::Result<C2*, E2*> result(Err(&e2));
mozilla::Result<C1*, E1*> copied(std::move(result));
MOZ_RELEASE_ASSERT(copied.inspectErr() == &e2);
}
}
/* * */
int main() {
BasicTests();
InPlaceConstructionTests();
TypeConversionTests();
EmptyValueTest();
MapTest();
MapErrTest();
OrElseTest();
AndThenTest();
UniquePtrTest();
ZeroIsEmptyErrorTest();
UpcastTest();
return 0;
}