catto
/
shadPS4
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add Result<T, E> type

This commit is contained in:
wheremyfoodat 2023-10-19 18:39:20 +03:00
parent 189d177692
commit 077b254a4f
4 changed files with 1244 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
CMakeLists.txt
View File

@ -19,6 +19,7 @@ include_directories(third-party/zydis/include/Zydis)
include_directories(third-party/winpthread/include) include_directories(third-party/winpthread/include)
include_directories(third-party/vulkan/include) include_directories(third-party/vulkan/include)
include_directories(third-party/xxhash/include) include_directories(third-party/xxhash/include)
include_directories(third-party/result/include)
add_subdirectory("third-party") add_subdirectory("third-party")
#=================== EXAMPLE =================== #=================== EXAMPLE ===================
include_directories(src) include_directories(src)

201
third-party/result/LICENSE vendored Normal file
View File

@ -0,0 +1,201 @@
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "{}"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright {2016} {Mathieu Stefani}
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

132
third-party/result/README.md vendored Normal file
View File

@ -0,0 +1,132 @@
# Result
This is an adaption of [https://github.com/oktal/result](https://github.com/oktal/result). Make sure to support the original library!
## Overview
`Result<T, E>` is a template type that can be used to return and propage errors. It can be used to replace
exceptions in context where they are not allowed or too slow to be used. `Result<T, E>` is an algebraic data
type of `Ok(T)` that represents success and `Err(E)` representing an error.
Design of this class has been mainly inspired by Rust's [std::result](https://doc.rust-lang.org/std/result/)
```
struct Request {
};
struct Error {
enum class Kind {
Timeout,
Invalid,
TooLong
}
Error(Kind kind, std::string text);
Kind kind;
std::string text;
};
Result<Request, Error> parseRequest(const std::string& payload) {
if (payload.size() > 512) return Err(Error(Kind::TooLong, "Request exceeded maximum allowed size (512 bytes)"));
Request request;
return Ok(request);
}
std::string payload = receivePayload();
auto request = parseRequest(payload).expect("Failed to parse request");
```
To return a successfull `Result`, use the `Ok()` function. To return an error one, use the `Err()` function.
## Extract and unwrap
To extract the value from a `Result<T, E>` type, you can use the `expect()` function that will yield the value
of an `Ok(T)` or terminate the program with an error message passed as a parameter.
```
Result<uint32_t, uint32_t> r1 = Ok(3u);
auto val = r1.expect("Failed to retrieve the value");
assert(val == 3);
```
`unwrap()` can also be used to extract the value of a `Result`, yielding the value of an `Ok(T)` value or terminating
the program otherwise:
```
Result<uint32_t, uint32_t> r1 = Ok(3u);
auto val = r1.unwrap();
assert(val == 3);
```
Instead a terminating the program, `unwrapOr` can be used to return a default value for an `Err(E)` Result:
```
Result<uint32_t, uint32_t> r1 = Err(9u);
auto val = r1.unwrapOr(0);
assert(val == 0);
```
## Map and bind
To transform (or map) a `Result<T, E>` to a `Result<U, E>`, `Result` provides a `map` member function.
`map` will apply a function to a contained `Ok(T)` value and will return the result of the transformation,
and will leave an `Err(E)` untouched:
```
std::string stringify(int val) { return std::to_string(val); }
Result<uint32_t, uint32_t> r1 = Ok(2u);
auto r2 = r1.map(stringify); // Maps a Result<uint32_t, uint32_t> to Result<std::string, uint32_t>
assert(r2.unwrap(), "2");
```
Note that `map` should return a simple value and not a `Result<U, E>`. A function returning nothing (`void`)
applied to a `Result<T, E>` will yield a `Result<void, E>`.
To map a function to a contained `Err(E)` value, use the `mapError` function.
To *bind* a `Result<T, E>` to a `Result<U, E>`, you can use the `andThen` member function:
```
Result<uint32_t, uint32_t> square(uint32_t val) { return Ok(val * val); }
Result<uint32_t, uint32_t> r1 = Ok(3u);
auto r2 = r1.andThen(square);
assert(r2.unwrap(), 9);
```
Use `orElse` to apply a function to a contained `Err(E)` value:
```
Result<uint32_t, uint32_t> identity(uint32_t val) { return Ok(val); }
Result<uint32_t, uint32_t> r1 = Err(3u);
assert(r1.andThen(identity).orElse(square).unwrap(), 9);
```
## The TRY macro
Like Rust, a `TRY` macro is also provided that comes in handy when writing code that calls a lot of functions returning a `Result`.
the `TRY` macro will simply call its argument and short-cirtcuit the function returning an `Err(E)` if the operation returned an error `Result`:
```
Result<void, IoError> copy(int srcFd, const char* dstFile) {
auto fd = TRY(open(dstFile));
auto data = TRY(read(srcFd));
TRY(write(fd, data));
return Ok();
}
```
Note that this macro uses a special extension called *compound statement* only supported by gcc and clang

910
third-party/result/include/result.hpp vendored Normal file
View File

@ -0,0 +1,910 @@
/*
Mathieu Stefani, 03 mai 2016
This header provides a Result type that can be used to replace exceptions in code
that has to handle error.
Result<T, E> can be used to return and propagate an error to the caller. Result<T, E> is an algebraic
data type that can either Ok(T) to represent success or Err(E) to represent an error.
*/
#pragma once
#include <iostream>
#include <functional>
#include <type_traits>
namespace types {
template<typename T>
struct Ok {
Ok(const T& val) : val(val) { }
Ok(T&& val) : val(std::move(val)) { }
T val;
};
template<>
struct Ok<void> { };
template<typename E>
struct Err {
Err(const E& val) : val(val) { }
Err(E&& val) : val(std::move(val)) { }
E val;
};
}
template<typename T, typename CleanT = typename std::decay<T>::type>
types::Ok<CleanT> Ok(T&& val) {
return types::Ok<CleanT>(std::forward<T>(val));
}
inline types::Ok<void> Ok() {
return types::Ok<void>();
}
template<typename E, typename CleanE = typename std::decay<E>::type>
types::Err<CleanE> Err(E&& val) {
return types::Err<CleanE>(std::forward<E>(val));
}
namespace Rust {
template<typename T, typename E> struct Result;
}
namespace details {
template<typename ...> struct void_t { typedef void type; };
namespace impl {
template<typename Func> struct result_of;
template<typename Ret, typename Cls, typename... Args>
struct result_of<Ret (Cls::*)(Args...)> : public result_of<Ret (Args...)> { };
template<typename Ret, typename... Args>
struct result_of<Ret (Args...)> {
typedef Ret type;
};
}
template<typename Func>
struct result_of : public impl::result_of<decltype(&Func::operator())> { };
template<typename Ret, typename Cls, typename... Args>
struct result_of<Ret (Cls::*) (Args...) const> {
typedef Ret type;
};
template<typename Ret, typename... Args>
struct result_of<Ret (*)(Args...)> {
typedef Ret type;
};
template<typename R>
struct ResultOkType { typedef typename std::decay<R>::type type; };
template<typename T, typename E>
struct ResultOkType<Rust::Result<T, E>> {
typedef T type;
};
template<typename R>
struct ResultErrType { typedef R type; };
template<typename T, typename E>
struct ResultErrType<Rust::Result<T, E>> {
typedef typename std::remove_reference<E>::type type;
};
template<typename R> struct IsResult : public std::false_type { };
template<typename T, typename E>
struct IsResult<Rust::Result<T, E>> : public std::true_type { };
namespace ok {
namespace impl {
template<typename T> struct Map;
template<typename Ret, typename Cls, typename Arg>
struct Map<Ret (Cls::*)(Arg) const> : public Map<Ret (Arg)> { };
template<typename Ret, typename Cls, typename Arg>
struct Map<Ret (Cls::*)(Arg)> : public Map<Ret (Arg)> { };
// General implementation
template<typename Ret, typename Arg>
struct Map<Ret (Arg)> {
static_assert(!IsResult<Ret>::value,
"Can not map a callback returning a Result, use andThen instead");
template<typename T, typename E, typename Func>
static Rust::Result<Ret, E> map(const Rust::Result<T, E>& result, Func func) {
static_assert(
std::is_same<T, Arg>::value ||
std::is_convertible<T, Arg>::value,
"Incompatible types detected");
if (result.isOk()) {
auto res = func(result.storage().template get<T>());
return types::Ok<Ret>(std::move(res));
}
return types::Err<E>(result.storage().template get<E>());
}
};
// Specialization for callback returning void
template<typename Arg>
struct Map<void (Arg)> {
template<typename T, typename E, typename Func>
static Rust::Result<void, E> map(const Rust::Result<T, E>& result, Func func) {
if (result.isOk()) {
func(result.storage().template get<T>());
return types::Ok<void>();
}
return types::Err<E>(result.storage().template get<E>());
}
};
// Specialization for a void Result
template<typename Ret>
struct Map<Ret (void)> {
template<typename T, typename E, typename Func>
static Rust::Result<Ret, E> map(const Rust::Result<T, E>& result, Func func) {
static_assert(std::is_same<T, void>::value,
"Can not map a void callback on a non-void Result");
if (result.isOk()) {
auto ret = func();
return types::Ok<Ret>(std::move(ret));
}
return types::Err<E>(result.storage().template get<E>());
}
};
// Specialization for callback returning void on a void Result
template<>
struct Map<void (void)> {
template<typename T, typename E, typename Func>
static Rust::Result<void, E> map(const Rust::Result<T, E>& result, Func func) {
static_assert(std::is_same<T, void>::value,
"Can not map a void callback on a non-void Result");
if (result.isOk()) {
func();
return types::Ok<void>();
}
return types::Err<E>(result.storage().template get<E>());
}
};
// General specialization for a callback returning a Result
template<typename U, typename E, typename Arg>
struct Map<Rust::Result<U, E> (Arg)> {
template<typename T, typename Func>
static Rust::Result<U, E> map(const Rust::Result<T, E>& result, Func func) {
static_assert(
std::is_same<T, Arg>::value ||
std::is_convertible<T, Arg>::value,
"Incompatible types detected");
if (result.isOk()) {
auto res = func(result.storage().template get<T>());
return res;
}
return types::Err<E>(result.storage().template get<E>());
}
};
// Specialization for a void callback returning a Result
template<typename U, typename E>
struct Map<Rust::Result<U, E> (void)> {
template<typename T, typename Func>
static Rust::Result<U, E> map(const Rust::Result<T, E>& result, Func func) {
static_assert(std::is_same<T, void>::value, "Can not call a void-callback on a non-void Result");
if (result.isOk()) {
auto res = func();
return res;
}
return types::Err<E>(result.storage().template get<E>());
}
};
} // namespace impl
template<typename Func> struct Map : public impl::Map<decltype(&Func::operator())> { };
template<typename Ret, typename... Args>
struct Map<Ret (*) (Args...)> : public impl::Map<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Map<Ret (Cls::*) (Args...)> : public impl::Map<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Map<Ret (Cls::*) (Args...) const> : public impl::Map<Ret (Args...)> { };
template<typename Ret, typename... Args>
struct Map<std::function<Ret (Args...)>> : public impl::Map<Ret (Args...)> { };
} // namespace ok
namespace err {
namespace impl {
template<typename T> struct Map;
template<typename Ret, typename Cls, typename Arg>
struct Map<Ret (Cls::*)(Arg) const> {
static_assert(!IsResult<Ret>::value,
"Can not map a callback returning a Result, use orElse instead");
template<typename T, typename E, typename Func>
static Rust::Result<T, Ret> map(const Rust::Result<T, E>& result, Func func) {
if (result.isErr()) {
auto res = func(result.storage().template get<E>());
return types::Err<Ret>(res);
}
return types::Ok<T>(result.storage().template get<T>());
}
template<typename E, typename Func>
static Rust::Result<void, Ret> map(const Rust::Result<void, E>& result, Func func) {
if (result.isErr()) {
auto res = func(result.storage().template get<E>());
return types::Err<Ret>(res);
}
return types::Ok<void>();
}
};
} // namespace impl
template<typename Func> struct Map : public impl::Map<decltype(&Func::operator())> { };
} // namespace err;
namespace And {
namespace impl {
template<typename Func> struct Then;
template<typename Ret, typename... Args>
struct Then<Ret (*)(Args...)> : public Then<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Then<Ret (Cls::*)(Args...)> : public Then<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Then<Ret (Cls::*)(Args...) const> : public Then<Ret (Args...)> { };
template<typename Ret, typename Arg>
struct Then<Ret (Arg)> {
static_assert(std::is_same<Ret, void>::value,
"then() should not return anything, use map() instead");
template<typename T, typename E, typename Func>
static Rust::Result<T, E> then(const Rust::Result<T, E>& result, Func func) {
if (result.isOk()) {
func(result.storage().template get<T>());
}
return result;
}
};
template<typename Ret>
struct Then<Ret (void)> {
static_assert(std::is_same<Ret, void>::value,
"then() should not return anything, use map() instead");
template<typename T, typename E, typename Func>
static Rust::Result<T, E> then(const Rust::Result<T, E>& result, Func func) {
static_assert(std::is_same<T, void>::value, "Can not call a void-callback on a non-void Result");
if (result.isOk()) {
func();
}
return result;
}
};
} // namespace impl
template<typename Func>
struct Then : public impl::Then<decltype(&Func::operator())> { };
template<typename Ret, typename... Args>
struct Then<Ret (*) (Args...)> : public impl::Then<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Then<Ret (Cls::*)(Args...)> : public impl::Then<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Then<Ret (Cls::*)(Args...) const> : public impl::Then<Ret (Args...)> { };
} // namespace And
namespace Or {
namespace impl {
template<typename Func> struct Else;
template<typename Ret, typename... Args>
struct Else<Ret (*)(Args...)> : public Else<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Else<Ret (Cls::*)(Args...)> : public Else<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Else<Ret (Cls::*)(Args...) const> : public Else<Ret (Args...)> { };
template<typename T, typename F, typename Arg>
struct Else<Rust::Result<T, F> (Arg)> {
template<typename E, typename Func>
static Rust::Result<T, F> orElse(const Rust::Result<T, E>& result, Func func) {
static_assert(
std::is_same<E, Arg>::value ||
std::is_convertible<E, Arg>::value,
"Incompatible types detected");
if (result.isErr()) {
auto res = func(result.storage().template get<E>());
return res;
}
return types::Ok<T>(result.storage().template get<T>());
}
template<typename E, typename Func>
static Rust::Result<void, F> orElse(const Rust::Result<void, E>& result, Func func) {
if (result.isErr()) {
auto res = func(result.storage().template get<E>());
return res;
}
return types::Ok<void>();
}
};
template<typename T, typename F>
struct Else<Rust::Result<T, F> (void)> {
template<typename E, typename Func>
static Rust::Result<T, F> orElse(const Rust::Result<T, E>& result, Func func) {
static_assert(std::is_same<T, void>::value,
"Can not call a void-callback on a non-void Result");
if (result.isErr()) {
auto res = func();
return res;
}
return types::Ok<T>(result.storage().template get<T>());
}
template<typename E, typename Func>
static Rust::Result<void, F> orElse(const Rust::Result<void, E>& result, Func func) {
if (result.isErr()) {
auto res = func();
return res;
}
return types::Ok<void>();
}
};
} // namespace impl
template<typename Func>
struct Else : public impl::Else<decltype(&Func::operator())> { };
template<typename Ret, typename... Args>
struct Else<Ret (*) (Args...)> : public impl::Else<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Else<Ret (Cls::*)(Args...)> : public impl::Else<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Else<Ret (Cls::*)(Args...) const> : public impl::Else<Ret (Args...)> { };
} // namespace Or
namespace Other {
namespace impl {
template<typename Func> struct Wise;
template<typename Ret, typename... Args>
struct Wise<Ret (*)(Args...)> : public Wise<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Wise<Ret (Cls::*)(Args...)> : public Wise<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Wise<Ret (Cls::*)(Args...) const> : public Wise<Ret (Args...)> { };
template<typename Ret, typename Arg>
struct Wise<Ret (Arg)> {
template<typename T, typename E, typename Func>
static Rust::Result<T, E> otherwise(const Rust::Result<T, E>& result, Func func) {
static_assert(
std::is_same<E, Arg>::value ||
std::is_convertible<E, Arg>::value,
"Incompatible types detected");
static_assert(std::is_same<Ret, void>::value,
"callback should not return anything, use mapError() for that");
if (result.isErr()) {
func(result.storage().template get<E>());
}
return result;
}
};
} // namespace impl
template<typename Func>
struct Wise : public impl::Wise<decltype(&Func::operator())> { };
template<typename Ret, typename... Args>
struct Wise<Ret (*) (Args...)> : public impl::Wise<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Wise<Ret (Cls::*)(Args...)> : public impl::Wise<Ret (Args...)> { };
template<typename Ret, typename Cls, typename... Args>
struct Wise<Ret (Cls::*)(Args...) const> : public impl::Wise<Ret (Args...)> { };
} // namespace Other
template<typename T, typename E, typename Func,
typename Ret =
Rust::Result<
typename details::ResultOkType<
typename details::result_of<Func>::type
>::type,
E>
>
Ret map(const Rust::Result<T, E>& result, Func func) {
return ok::Map<Func>::map(result, func);
}
template<typename T, typename E, typename Func,
typename Ret =
Rust::Result<T,
typename details::ResultErrType<
typename details::result_of<Func>::type
>::type
>
>
Ret mapError(const Rust::Result<T, E>& result, Func func) {
return err::Map<Func>::map(result, func);
}
template<typename T, typename E, typename Func>
Rust::Result<T, E> then(const Rust::Result<T, E>& result, Func func) {
return And::Then<Func>::then(result, func);
}
template<typename T, typename E, typename Func>
Rust::Result<T, E> otherwise(const Rust::Result<T, E>& result, Func func) {
return Other::Wise<Func>::otherwise(result, func);
}
template<typename T, typename E, typename Func,
typename Ret =
Rust::Result<T,
typename details::ResultErrType<
typename details::result_of<Func>::type
>::type
>
>
Ret orElse(const Rust::Result<T, E>& result, Func func) {
return Or::Else<Func>::orElse(result, func);
}
struct ok_tag { };
struct err_tag { };
template<typename T, typename E>
struct Storage {
static constexpr size_t Size = sizeof(T) > sizeof(E) ? sizeof(T) : sizeof(E);
static constexpr size_t Align = sizeof(T) > sizeof(E) ? alignof(T) : alignof(E);
typedef typename std::aligned_storage<Size, Align>::type type;
Storage()
: initialized_(false)
{ }
void construct(types::Ok<T> ok)
{
new (&storage_) T(ok.val);
initialized_ = true;
}
void construct(types::Err<E> err)
{
new (&storage_) E(err.val);
initialized_ = true;
}
template<typename U>
void rawConstruct(U&& val) {
typedef typename std::decay<U>::type CleanU;
new (&storage_) CleanU(std::forward<U>(val));
initialized_ = true;
}
template<typename U>
const U& get() const {
return *reinterpret_cast<const U *>(&storage_);
}
template<typename U>
U& get() {
return *reinterpret_cast<U *>(&storage_);
}
void destroy(ok_tag) {
if (initialized_) {
get<T>().~T();
initialized_ = false;
}
}
void destroy(err_tag) {
if (initialized_) {
get<E>().~E();
initialized_ = false;
}
}
type storage_;
bool initialized_;
};
template<typename E>
struct Storage<void, E> {
typedef typename std::aligned_storage<sizeof(E), alignof(E)>::type type;
void construct(types::Ok<void>)
{
initialized_ = true;
}
void construct(types::Err<E> err)
{
new (&storage_) E(err.val);
initialized_ = true;
}
template<typename U>
void rawConstruct(U&& val) {
typedef typename std::decay<U>::type CleanU;
new (&storage_) CleanU(std::forward<U>(val));
initialized_ = true;
}
void destroy(ok_tag) { initialized_ = false; }
void destroy(err_tag) {
if (initialized_) {
get<E>().~E(); initialized_ = false;
}
}
template<typename U>
const U& get() const {
return *reinterpret_cast<const U *>(&storage_);
}
template<typename U>
U& get() {
return *reinterpret_cast<U *>(&storage_);
}
type storage_;
bool initialized_;
};
template<typename T, typename E>
struct Constructor {
static void move(Storage<T, E>&& src, Storage<T, E>& dst, ok_tag) {
dst.rawConstruct(std::move(src.template get<T>()));
src.destroy(ok_tag());
}
static void copy(const Storage<T, E>& src, Storage<T, E>& dst, ok_tag) {
dst.rawConstruct(src.template get<T>());
}
static void move(Storage<T, E>&& src, Storage<T, E>& dst, err_tag) {
dst.rawConstruct(std::move(src.template get<E>()));
src.destroy(err_tag());
}
static void copy(const Storage<T, E>& src, Storage<T, E>& dst, err_tag) {
dst.rawConstruct(src.template get<E>());
}
};
template<typename E>
struct Constructor<void, E> {
static void move(Storage<void, E>&& src, Storage<void, E>& dst, ok_tag) {
}
static void copy(const Storage<void, E>& src, Storage<void, E>& dst, ok_tag) {
}
static void move(Storage<void, E>&& src, Storage<void, E>& dst, err_tag) {
dst.rawConstruct(std::move(src.template get<E>()));
src.destroy(err_tag());
}
static void copy(const Storage<void, E>& src, Storage<void, E>& dst, err_tag) {
dst.rawConstruct(src.template get<E>());
}
};
} // namespace details
namespace rpog {
template<typename T, typename = void> struct EqualityComparable : std::false_type { };
template<typename T>
struct EqualityComparable<T,
typename std::enable_if<
true,
typename details::void_t<decltype(std::declval<T>() == std::declval<T>())>::type
>::type
> : std::true_type
{
};
} // namespace rpog
namespace Rust {
template<typename T, typename E>
struct Result {
static_assert(!std::is_same<E, void>::value, "void error type is not allowed");
typedef details::Storage<T, E> storage_type;
Result(types::Ok<T> ok)
: ok_(true)
{
storage_.construct(std::move(ok));
}
Result(types::Err<E> err)
: ok_(false)
{
storage_.construct(std::move(err));
}
Result(Result&& other) {
if (other.isOk()) {
details::Constructor<T, E>::move(std::move(other.storage_), storage_, details::ok_tag());
ok_ = true;
} else {
details::Constructor<T, E>::move(std::move(other.storage_), storage_, details::err_tag());
ok_ = false;
}
}
Result(const Result& other) {
if (other.isOk()) {
details::Constructor<T, E>::copy(other.storage_, storage_, details::ok_tag());
ok_ = true;
} else {
details::Constructor<T, E>::copy(other.storage_, storage_, details::err_tag());
ok_ = false;
}
}
~Result() {
if (ok_)
storage_.destroy(details::ok_tag());
else
storage_.destroy(details::err_tag());
}
bool isOk() const {
return ok_;
}
bool isErr() const {
return !ok_;
}
T expect(const char* str) const {
if (!isOk()) {
std::fprintf(stderr, "%s\n", str);
std::terminate();
}
return expect_impl(std::is_same<T, void>());
}
template<typename Func,
typename Ret =
Result<
typename details::ResultOkType<
typename details::result_of<Func>::type
>::type,
E>
>
Ret map(Func func) const {
return details::map(*this, func);
}
template<typename Func,
typename Ret =
Result<T,
typename details::ResultErrType<
typename details::result_of<Func>::type
>::type
>
>
Ret mapError(Func func) const {
return details::mapError(*this, func);
}
template<typename Func>
Result<T, E> then(Func func) const {
return details::then(*this, func);
}
template<typename Func>
Result<T, E> otherwise(Func func) const {
return details::otherwise(*this, func);
}
template<typename Func,
typename Ret =
Result<T,
typename details::ResultErrType<
typename details::result_of<Func>::type
>::type
>
>
Ret orElse(Func func) const {
return details::orElse(*this, func);
}
storage_type& storage() {
return storage_;
}
const storage_type& storage() const {
return storage_;
}
template<typename U = T>
typename std::enable_if<
!std::is_same<U, void>::value,
U
>::type
unwrapOr(const U& defaultValue) const {
if (isOk()) {
return storage().template get<U>();
}
return defaultValue;
}
template<typename U = T>
typename std::enable_if<
!std::is_same<U, void>::value,
U
>::type
unwrap() const {
if (isOk()) {
return storage().template get<U>();
}
std::fprintf(stderr, "Attempting to unwrap an error Result\n");
std::terminate();
}
E unwrapErr() const {
if (isErr()) {
return storage().template get<E>();
}
std::fprintf(stderr, "Attempting to unwrapErr an ok Result\n");
std::terminate();
}
private:
T expect_impl(std::true_type) const { }
T expect_impl(std::false_type) const { return storage_.template get<T>(); }
bool ok_;
storage_type storage_;
};
template<typename T, typename E>
bool operator==(const Rust::Result<T, E>& lhs, const Rust::Result<T, E>& rhs) {
static_assert(rpog::EqualityComparable<T>::value, "T must be EqualityComparable for Result to be comparable");
static_assert(rpog::EqualityComparable<E>::value, "E must be EqualityComparable for Result to be comparable");
if (lhs.isOk() && rhs.isOk()) {
return lhs.storage().template get<T>() == rhs.storage().template get<T>();
}
if (lhs.isErr() && rhs.isErr()) {
return lhs.storage().template get<E>() == rhs.storage().template get<E>();
}
}
template<typename T, typename E>
bool operator==(const Rust::Result<T, E>& lhs, types::Ok<T> ok) {
static_assert(rpog::EqualityComparable<T>::value, "T must be EqualityComparable for Result to be comparable");
if (!lhs.isOk()) return false;
return lhs.storage().template get<T>() == ok.val;
}
template<typename E>
bool operator==(const Rust::Result<void, E>& lhs, types::Ok<void>) {
return lhs.isOk();
}
template<typename T, typename E>
bool operator==(const Rust::Result<T, E>& lhs, types::Err<E> err) {
static_assert(rpog::EqualityComparable<E>::value, "E must be EqualityComparable for Result to be comparable");
if (!lhs.isErr()) return false;
return lhs.storage().template get<E>() == err.val;
}
} // end namespace Rust
#define TRY(...) \
({ \
auto res = __VA_ARGS__; \
if (!res.isOk()) { \
typedef details::ResultErrType<decltype(res)>::type E; \
return types::Err<E>(res.storage().get<E>()); \
} \
typedef details::ResultOkType<decltype(res)>::type T; \
res.storage().get<T>(); \
})