debug_stream.hpp

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// Copyright (c) 2014-2018 Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
// Copyright (c) 2014-2018 Centre national de la recherche scientifique (CNRS)
// Copyright (c) 2018 Simons Foundation
//
// 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 may obtain a copy of the License at
//     https://www.gnu.org/licenses/gpl-3.0.txt
//
// Authors: Olivier Parcollet, Nils Wentzell

 
#pragma once
 
#include <functional>
#include <ostream>
 
namespace triqs::utility {

  class debug_stream {
    std::ostream *out; // NOLINT
    std::function<bool()> condition;
 
    public:
    debug_stream(std::ostream *out_, std::function<bool()> condition) : out(out_), condition(condition) {}

    debug_stream(std::ostream *out_) : out(out_) {}

    template <class T> debug_stream &operator<<([[maybe_unused]] T const &x) {
#ifdef TRIQS_DEBUG
      if (condition && condition()) (*out) << x;
#endif
      return *this;
    }

    using CoutType = std::basic_ostream<char, std::char_traits<char>>;

    using StandardEndLine = CoutType &(*)(CoutType &);

    debug_stream &operator<<([[maybe_unused]] StandardEndLine manip) {
#ifdef TRIQS_DEBUG
      if (condition && condition()) manip(*out);
#endif
      return *this;
    }
  };
 
} // namespace triqs::utility