102 lines
1.9 KiB
C++
102 lines
1.9 KiB
C++
//
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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_IMPL_NULL_RESOURCE_IPP
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#define BOOST_JSON_IMPL_NULL_RESOURCE_IPP
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#include <boost/json/null_resource.hpp>
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#include <boost/json/detail/except.hpp>
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BOOST_JSON_NS_BEGIN
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namespace detail {
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/** A resource which always fails.
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This memory resource always throws the exception
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`std::bad_alloc` in calls to `allocate`.
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*/
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class null_resource final
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: public memory_resource
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{
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public:
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/// Copy constructor (deleted)
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null_resource(
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null_resource const&) = delete;
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/// Copy assignment (deleted)
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null_resource& operator=(
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null_resource const&) = delete;
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/** Destructor
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This destroys the resource.
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@par Complexity
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Constant.
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@part Exception Safety
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No-throw guarantee.
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*/
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~null_resource() noexcept = default;
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/** Constructor
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This constructs the resource.
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@par Complexity
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Constant.
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@par Exception Safety
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No-throw guarantee.
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*/
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/** @{ */
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null_resource() noexcept = default;
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protected:
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void*
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do_allocate(
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std::size_t,
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std::size_t) override
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{
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detail::throw_bad_alloc(
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BOOST_JSON_SOURCE_POS);
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}
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void
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do_deallocate(
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void*,
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std::size_t,
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std::size_t) override
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{
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// do nothing
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}
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bool
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do_is_equal(
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memory_resource const& mr
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) const noexcept override
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{
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return this == &mr;
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}
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};
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} // detail
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memory_resource*
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get_null_resource() noexcept
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{
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static detail::null_resource mr;
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return &mr;
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}
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BOOST_JSON_NS_END
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#endif
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