//
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// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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// Official repository: https://github.com/boostorg/json
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//
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#ifndef BOOST_JSON_DEFAULT_RESOURCE_HPP
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#define BOOST_JSON_DEFAULT_RESOURCE_HPP
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#include <boost/json/detail/config.hpp>
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#include <new>
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BOOST_JSON_NS_BEGIN
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namespace detail {
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#ifdef _MSC_VER
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#pragma warning(push)
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#pragma warning(disable: 4251) // class needs to have dll-interface to be used by clients of class
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#pragma warning(disable: 4275) // non dll-interface class used as base for dll-interface class
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#endif
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// A simple memory resource that uses operator new and delete.
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class
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BOOST_SYMBOL_VISIBLE
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BOOST_JSON_CLASS_DECL
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default_resource final
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: public memory_resource
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{
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union holder;
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#ifndef BOOST_JSON_WEAK_CONSTINIT
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# ifndef BOOST_JSON_NO_DESTROY
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static holder instance_;
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# else
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BOOST_JSON_NO_DESTROY
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static default_resource instance_;
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# endif
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#endif
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public:
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static
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memory_resource*
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get() noexcept
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{
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#ifdef BOOST_JSON_WEAK_CONSTINIT
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static default_resource instance_;
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#endif
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return reinterpret_cast<memory_resource*>(
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reinterpret_cast<std::uintptr_t*>(
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&instance_));
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}
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~default_resource();
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void*
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do_allocate(
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std::size_t n,
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std::size_t) override;
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void
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do_deallocate(
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void* p,
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std::size_t,
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std::size_t) override;
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bool
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do_is_equal(
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memory_resource const& mr) const noexcept override;
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};
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#ifdef _MSC_VER
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#pragma warning(pop)
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#endif
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union default_resource::
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holder
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{
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#ifndef BOOST_JSON_WEAK_CONSTINIT
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constexpr
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#endif
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holder()
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: mr()
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{
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}
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~holder()
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{
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}
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default_resource mr;
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};
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} // detail
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BOOST_JSON_NS_END
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#endif
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