空白区切り出力、iostreamのオーバーロード
(src/base/io.hpp)

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• Last update: 2026-10-11 23:34:07+09:00
• Include: #include "src/base/io.hpp"

STL のコンテナを >> / << で入出力できるようにし、空白区切りで出力する print を追加します。

std::vector<std::pair<int, int>> v(n);
std::cin >> v;                  // 2n 個の整数を読む
print(v);                       // "1 2 3 4" のように空白区切りで出力して改行
print(1, "a", 2.5);             // "1 a 2.5"
err(x, y);                      // 標準エラー出力に出す

入出力演算子

ネストした型 (vector<pair<int, int>> など) もそのまま入出力できます。

型	>>	<<
std::pair	✓	✓
std::tuple	✓	✓
std::array	✓	✓
std::vector	✓ (あらかじめ要素数を決めておく)	✓
std::set		✓

出力は要素を空白 1 つで区切ります。

関数

関数	説明
print(x, ...)	引数を空白区切りで標準出力に出して改行。引数なしなら改行だけ
err(x, ...)	引数を空白区切りで標準エラー出力に出して改行 (std::endl でフラッシュする)

関連

• デバッグ用に型ごと出力するなら repr の DEBUG(x)

Required by

• マクロ (rep など) (src/base/macro.hpp)

Verified with

• test/aoj/1160.test.cpp
• test/aoj/cgl-3-a.test.cpp
• test/aoj/cgl-3-b.test.cpp
• test/aoj/cgl-3-c.test.cpp
• test/aoj/itp1-2-c.test.cpp
• test/aoj/itp1-6-a.test.cpp
• test/aoj/itp2-5-a.1.test.cpp
• test/aoj/itp2-5-b.test.cpp
• test/unittest/io.test.cpp
• test/unittest/macro.test.cpp
• test/yosupo/convolution-mod-2-64.test.cpp

Code

#pragma once
/**
 * @file io.hpp
 * @brief 空白区切り出力、iostreamのオーバーロード
 */

#include <array>
#include <iostream>
#include <set>
#include <utility>
#include <tuple>
#include <vector>

// ネストした型 (pair<vector<int>, int> など) を扱えるように先に宣言しておく
template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::pair<T1, T2>& p);
template <typename... Types, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::tuple<Types...>& p);
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::array<T, N>& a);
template <typename T, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::vector<T>& v);
template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::pair<T1, T2>& p);
template <typename... Types, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::tuple<Types...>& p);
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::array<T, N>& a);
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::vector<T>& v);
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::set<T>& s);

namespace tuple_io {
    template <typename Tuple, size_t I, typename CharT, typename Traits>
    std::basic_istream<CharT, Traits>& read_tuple(std::basic_istream<CharT, Traits>& is, Tuple& t) {
        is >> std::get<I>(t);
        if constexpr (I + 1 < std::tuple_size_v<Tuple>) {
            return read_tuple<Tuple, I + 1>(is, t);
        }
        return is;
    }
    template <typename Tuple, size_t I, typename CharT, typename Traits>
    std::basic_ostream<CharT, Traits>& write_tuple(std::basic_ostream<CharT, Traits>& os, const Tuple& t) {
        os << std::get<I>(t);
        if constexpr (I + 1 < std::tuple_size_v<Tuple>) {
            os << CharT(' ');
            return write_tuple<Tuple, I + 1>(os, t);
        }
        return os;
    }
};

template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::pair<T1, T2>& p) {
    is >> p.first >> p.second;
    return is;
}
template <typename... Types, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::tuple<Types...>& p) {
    return tuple_io::read_tuple<std::tuple<Types...>, 0>(is, p);
}
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::array<T, N>& a) {
    for(auto& e : a) is >> e;
    return is;
}
template <typename T, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::vector<T>& v) {
    for(auto& e : v) is >> e;
    return is;
}

template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::pair<T1, T2>& p) {
    os << p.first << CharT(' ') << p.second;
    return os;
}
template <typename... Types, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::tuple<Types...>& p) {
    return tuple_io::write_tuple<std::tuple<Types...>, 0>(os, p);
}
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::array<T, N>& a) {
    for(size_t i = 0; i < N; ++i) {
        if(i) os << CharT(' ');
        os << a[i];
    }
    return os;
}
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::vector<T>& v) {
    for(size_t i = 0; i < v.size(); ++i) {
        if(i) os << CharT(' ');
        os << v[i];
    }
    return os;
}
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::set<T>& s) {
    for(auto itr = s.begin(); itr != s.end(); ++itr) {
        if(itr != s.begin()) os << CharT(' ');
        os << *itr;
    }
    return os;
}

/**
 * @brief 空行出力
 */
inline void print() { std::cout << '\n'; }
/**
 * @brief 出力して改行
 * 
 * @tparam T 型
 * @param x 出力する値
 */
template <typename T>
void print(const T& x) { std::cout << x << '\n'; }
/**
 * @brief 空白区切りで出力して改行
 * 
 * @tparam T 1つ目の要素の型
 * @tparam Tail 2つ目以降の要素の型
 * @param x 1つ目の要素
 * @param tail 2つ目以降の要素
 */
template <typename T, typename... Tail>
void print(const T& x, const Tail&... tail) {
    std::cout << x << ' ';
    print(tail...);
}

/**
 * @brief 標準エラー出力に空行出力
 */
inline void err() { std::cerr << std::endl; }
/**
 * @brief 標準エラー出力に出力して改行
 *
 * @tparam T 型
 * @param x 出力する値
 */
template <typename T>
void err(const T& x) { std::cerr << x << std::endl; }
/**
 * @brief 標準エラー出力に空白区切りで出力して改行
 *
 * @tparam T 1つ目の要素の型
 * @tparam Tail 2つ目以降の要素の型
 * @param x 1つ目の要素
 * @param tail 2つ目以降の要素
 */
template <typename T, typename... Tail>
void err(const T& x, const Tail&... tail) {
    std::cerr << x << ' ';
    err(tail...);
}

#line 2 "src/base/io.hpp"
/**
 * @file io.hpp
 * @brief 空白区切り出力、iostreamのオーバーロード
 */

#include <array>
#include <iostream>
#include <set>
#include <utility>
#include <tuple>
#include <vector>

// ネストした型 (pair<vector<int>, int> など) を扱えるように先に宣言しておく
template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::pair<T1, T2>& p);
template <typename... Types, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::tuple<Types...>& p);
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::array<T, N>& a);
template <typename T, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::vector<T>& v);
template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::pair<T1, T2>& p);
template <typename... Types, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::tuple<Types...>& p);
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::array<T, N>& a);
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::vector<T>& v);
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::set<T>& s);

namespace tuple_io {
    template <typename Tuple, size_t I, typename CharT, typename Traits>
    std::basic_istream<CharT, Traits>& read_tuple(std::basic_istream<CharT, Traits>& is, Tuple& t) {
        is >> std::get<I>(t);
        if constexpr (I + 1 < std::tuple_size_v<Tuple>) {
            return read_tuple<Tuple, I + 1>(is, t);
        }
        return is;
    }
    template <typename Tuple, size_t I, typename CharT, typename Traits>
    std::basic_ostream<CharT, Traits>& write_tuple(std::basic_ostream<CharT, Traits>& os, const Tuple& t) {
        os << std::get<I>(t);
        if constexpr (I + 1 < std::tuple_size_v<Tuple>) {
            os << CharT(' ');
            return write_tuple<Tuple, I + 1>(os, t);
        }
        return os;
    }
};

template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::pair<T1, T2>& p) {
    is >> p.first >> p.second;
    return is;
}
template <typename... Types, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::tuple<Types...>& p) {
    return tuple_io::read_tuple<std::tuple<Types...>, 0>(is, p);
}
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::array<T, N>& a) {
    for(auto& e : a) is >> e;
    return is;
}
template <typename T, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>& operator>>(std::basic_istream<CharT, Traits>& is, std::vector<T>& v) {
    for(auto& e : v) is >> e;
    return is;
}

template <typename T1, typename T2, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::pair<T1, T2>& p) {
    os << p.first << CharT(' ') << p.second;
    return os;
}
template <typename... Types, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::tuple<Types...>& p) {
    return tuple_io::write_tuple<std::tuple<Types...>, 0>(os, p);
}
template <typename T, size_t N, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::array<T, N>& a) {
    for(size_t i = 0; i < N; ++i) {
        if(i) os << CharT(' ');
        os << a[i];
    }
    return os;
}
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::vector<T>& v) {
    for(size_t i = 0; i < v.size(); ++i) {
        if(i) os << CharT(' ');
        os << v[i];
    }
    return os;
}
template <typename T, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::set<T>& s) {
    for(auto itr = s.begin(); itr != s.end(); ++itr) {
        if(itr != s.begin()) os << CharT(' ');
        os << *itr;
    }
    return os;
}

/**
 * @brief 空行出力
 */
inline void print() { std::cout << '\n'; }
/**
 * @brief 出力して改行
 * 
 * @tparam T 型
 * @param x 出力する値
 */
template <typename T>
void print(const T& x) { std::cout << x << '\n'; }
/**
 * @brief 空白区切りで出力して改行
 * 
 * @tparam T 1つ目の要素の型
 * @tparam Tail 2つ目以降の要素の型
 * @param x 1つ目の要素
 * @param tail 2つ目以降の要素
 */
template <typename T, typename... Tail>
void print(const T& x, const Tail&... tail) {
    std::cout << x << ' ';
    print(tail...);
}

/**
 * @brief 標準エラー出力に空行出力
 */
inline void err() { std::cerr << std::endl; }
/**
 * @brief 標準エラー出力に出力して改行
 *
 * @tparam T 型
 * @param x 出力する値
 */
template <typename T>
void err(const T& x) { std::cerr << x << std::endl; }
/**
 * @brief 標準エラー出力に空白区切りで出力して改行
 *
 * @tparam T 1つ目の要素の型
 * @tparam Tail 2つ目以降の要素の型
 * @param x 1つ目の要素
 * @param tail 2つ目以降の要素
 */
template <typename T, typename... Tail>
void err(const T& x, const Tail&... tail) {
    std::cerr << x << ' ';
    err(tail...);
}

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