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// Copyright (C) 2021-2022 Joel Rosdahl and other contributors
//
// See doc/AUTHORS.adoc for a complete list of contributors.
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program; if not, write to the Free Software Foundation, Inc., 51
// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#pragma once
#include <fmtmacros.hpp>
#include <string_view>
#include <utility>
namespace util {
// --- Interface ---
// Return value of `value` (where `T` typically is `nonstd::expected`) or throw
// an exception of type `E` with a `T::error_type` as the argument.
template<typename E, typename T>
typename T::value_type value_or_throw(const T& value);
template<typename E, typename T>
typename T::value_type value_or_throw(T&& value);
// Like above for with `prefix` added to the error message.
template<typename E, typename T>
typename T::value_type value_or_throw(const T& value, std::string_view prefix);
template<typename E, typename T>
typename T::value_type value_or_throw(T&& value, std::string_view prefix);
// Throw an exception of type `E` with a `T::error_type` as the argument if
// `value` is false.
template<typename E, typename T> void throw_on_error(const T& value);
// Like above for with `prefix` added to the error message.
template<typename E, typename T>
void throw_on_error(const T& value, std::string_view prefix);
#define TRY(x_) \
do { \
const auto result = x_; \
if (!result) { \
return nonstd::make_unexpected(result.error()); \
} \
} while (false)
// --- Inline implementations ---
template<typename E, typename T>
inline typename T::value_type
value_or_throw(const T& value)
{
if (value) {
return *value;
} else {
throw E(value.error());
}
}
template<typename E, typename T>
inline typename T::value_type
value_or_throw(T&& value)
{
if (value) {
return std::move(*value);
} else {
throw E(value.error());
}
}
template<typename E, typename T>
inline typename T::value_type
value_or_throw(const T& value, std::string_view prefix)
{
if (value) {
return *value;
} else {
throw E(FMT("{}{}", prefix, value.error()));
}
}
template<typename E, typename T>
inline typename T::value_type
value_or_throw(T&& value, std::string_view prefix)
{
if (value) {
return std::move(*value);
} else {
throw E(FMT("{}{}", prefix, value.error()));
}
}
template<typename E, typename T>
inline void
throw_on_error(const T& value)
{
if (!value) {
throw E(value.error());
}
}
// Like above for with `prefix` added to the error message.
template<typename E, typename T>
inline void
throw_on_error(const T& value, std::string_view prefix)
{
if (!value) {
throw E(FMT("{}{}", prefix, value.error()));
}
}
} // namespace util
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