variant.hpp

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// SPDX-FileCopyrightText: 2006-2024 Knut Reinert & Freie Universität Berlin
// SPDX-FileCopyrightText: 2016-2024 Knut Reinert & MPI für molekulare Genetik
// SPDX-License-Identifier: BSD-3-Clause
 
#pragma once
 
#include <variant>
 
#include <seqan3/core/debug_stream/debug_stream_type.hpp>
#include <seqan3/core/detail/template_inspection.hpp>
#include <seqan3/utility/type_traits/basic.hpp>
 
namespace seqan3
{
template <typename char_t, typename variant_type>
    requires detail::is_type_specialisation_of_v<std::remove_cvref_t<variant_type>, std::variant>
inline debug_stream_type<char_t> & operator<<(debug_stream_type<char_t> & s, variant_type && v)
{
    if (!v.valueless_by_exception())
        std::visit(
            [&s](auto && arg)
            {
                s << arg;
            },
            v);
    else
        s << "<VALUELESS_VARIANT>";
    return s;
}
 
 
} // namespace seqan3