OrangePi3588Media/include/utils/result.h
2026-01-13 08:28:55 +08:00

122 lines
3.7 KiB
C++

#pragma once
#include <string>
#include <type_traits>
#include <utility>
#include <variant>
namespace rk3588 {
// Error type for Result
class Error {
public:
Error() = default;
explicit Error(std::string message) : message_(std::move(message)) {}
Error(std::string message, int code) : message_(std::move(message)), code_(code) {}
const std::string& Message() const { return message_; }
int Code() const { return code_; }
bool Empty() const { return message_.empty(); }
explicit operator bool() const { return !message_.empty(); }
private:
std::string message_;
int code_ = 0;
};
// Result<T> for functions that return a value or error
template <typename T>
class Result {
public:
// NOLINTNEXTLINE: implicit conversion is intentional for ergonomic API
Result(T value) noexcept(std::is_nothrow_move_constructible_v<T>)
: data_(std::move(value)) {}
// NOLINTNEXTLINE: implicit conversion is intentional for ergonomic API
Result(Error error) noexcept : data_(std::move(error)) {}
bool Ok() const noexcept { return std::holds_alternative<T>(data_); }
bool Failed() const noexcept { return !Ok(); }
explicit operator bool() const noexcept { return Ok(); }
const T& Value() const& { return std::get<T>(data_); }
T& Value() & { return std::get<T>(data_); }
T&& Value() && { return std::get<T>(std::move(data_)); }
const T& ValueOr(const T& def) const& {
return Ok() ? std::get<T>(data_) : def;
}
const Error& Err() const { return std::get<Error>(data_); }
const std::string& ErrMessage() const {
static const std::string kEmpty;
return Failed() ? std::get<Error>(data_).Message() : kEmpty;
}
// Convenience: extract value, moving it out
T Take() { return std::get<T>(std::move(data_)); }
private:
std::variant<T, Error> data_;
};
// Result<void> specialization for functions that only succeed/fail
template <>
class Result<void> {
public:
Result() noexcept : error_() {}
// NOLINTNEXTLINE: implicit conversion is intentional for ergonomic API
Result(Error error) noexcept : error_(std::move(error)) {}
static Result Ok() noexcept { return Result(); }
static Result Fail(std::string message) { return Result(Error(std::move(message))); }
static Result Fail(std::string message, int code) {
return Result(Error(std::move(message), code));
}
bool IsOk() const noexcept { return error_.Empty(); }
bool Failed() const noexcept { return !IsOk(); }
explicit operator bool() const noexcept { return IsOk(); }
const Error& Err() const { return error_; }
const std::string& ErrMessage() const { return error_.Message(); }
private:
Error error_;
};
// Type aliases for common patterns
using Status = Result<void>;
// Helper macros for early return on error
#define RK_TRY(expr) \
do { \
auto _result = (expr); \
if (_result.Failed()) { \
return _result.Err(); \
} \
} while (0)
#define RK_TRY_ASSIGN(var, expr) \
auto _result_##var = (expr); \
if (_result_##var.Failed()) { \
return _result_##var.Err(); \
} \
var = std::move(_result_##var).Take()
// Helper functions
inline Status OkStatus() { return Status::Ok(); }
inline Status FailStatus(std::string msg) { return Status::Fail(std::move(msg)); }
template <typename T>
Result<T> MakeResult(T value) {
return Result<T>(std::move(value));
}
template <typename T>
Result<T> MakeError(std::string message) {
return Result<T>(Error(std::move(message)));
}
} // namespace rk3588