vn-verdnaturachat/ios/Pods/Flipper-Folly/folly/gen/IStream.h

61 lines
1.5 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* 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.
*/
#pragma once
#include <istream>
#include <string>
#include <folly/gen/Core.h>
namespace folly {
namespace gen {
namespace detail {
/**
* Generates lines by calling std::getline() on a given istream.
*/
class IStreamByLine : public GenImpl<std::string&&, IStreamByLine> {
public:
IStreamByLine(std::istream& in) : in_(in) {}
template <class Body>
bool apply(Body&& body) const {
for (std::string line; std::getline(in_, line);) {
if (!body(std::move(line))) {
return false;
}
}
return true;
}
// Technically, there could be infinite files (e.g. /dev/random), but people
// who open those can do so at their own risk.
static constexpr bool infinite = false;
private:
std::istream& in_;
};
} // namespace detail
inline detail::IStreamByLine byLine(std::istream& in) {
return detail::IStreamByLine(in);
}
} // namespace gen
} // namespace folly