// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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. template <typename T>
#pragma once
#include <tuple>
#include "arrow/util/string.h"
using arrow::internal::ToChars;
namespace arrow {
namespace internal {
namespace detail {
template <typename OStream, typename Tuple, size_t N>
struct TuplePrinter {
static void Print(OStream* os, const Tuple& t) {
TuplePrinter<OStream, Tuple, N - 1>::Print(os, t);
*os << std::get<N - 1>(t);
}
};
template <typename OStream, typename Tuple>
struct TuplePrinter<OStream, Tuple, 0> {
static void Print(OStream* os, const Tuple& t) {}
};
} // namespace detail
// Print elements from a tuple to a stream, in order.
// Typical use is to pack a bunch of existing values with std::forward_as_tuple()
// before passing it to this function.
template <typename OStream, typename... Args>
void PrintTuple(OStream* os, const std::tuple<Args&...>& tup) {
detail::TuplePrinter<OStream, std::tuple<Args&...>, sizeof...(Args)>::Print(os, tup);
}
template <typename Range, typename Separator>
struct PrintVector {
const Range& range_;
const Separator& separator_;
template <typename Os> // template to dodge inclusion of <ostream>
friend Os& operator<<(Os& os, PrintVector l) {
bool first = true;
os << "[";
for (const auto& element : l.range_) {
if (first) {
first = false;
} else {
os << l.separator_;
}
os << ToChars(element); // use ToChars to avoid locale dependence
}
os << "]";
return os;
}
};
template <typename Range, typename Separator>
PrintVector(const Range&, const Separator&) -> PrintVector<Range, Separator>;
} // namespace internal
} // namespace arrow