1060 lines
36 KiB
Plaintext
1060 lines
36 KiB
Plaintext
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// Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal.
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// Copyright (C) 2014-2016 Andrzej Krzemienski.
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//
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/optional for documentation.
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//
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// You are welcome to contact the maintainer at:
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// akrzemi1@gmail.com
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#ifndef BOOST_OPTIONAL_DETAIL_OLD_OPTIONAL_IMPLEMENTATION_AJK_28JAN2015_HPP
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#define BOOST_OPTIONAL_DETAIL_OLD_OPTIONAL_IMPLEMENTATION_AJK_28JAN2015_HPP
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#include <boost/detail/reference_content.hpp>
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#include <boost/mpl/bool.hpp>
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#include <boost/mpl/if.hpp>
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#include <boost/mpl/not.hpp>
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#include <boost/type_traits/is_reference.hpp>
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namespace boost {
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namespace optional_detail {
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template<class T>
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struct types_when_isnt_ref
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{
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typedef T const& reference_const_type ;
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typedef T & reference_type ;
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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typedef T && rval_reference_type ;
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typedef T && reference_type_of_temporary_wrapper;
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#ifdef BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
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// GCC 4.4 has support for an early draft of rvalue references. The conforming version below
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// causes warnings about returning references to a temporary.
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static T&& move(T&& r) { return r; }
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#else
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static rval_reference_type move(reference_type r) { return boost::move(r); }
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#endif
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#endif
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typedef T const* pointer_const_type ;
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typedef T * pointer_type ;
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typedef T const& argument_type ;
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} ;
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template<class T>
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struct types_when_is_ref
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{
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typedef BOOST_DEDUCED_TYPENAME remove_reference<T>::type raw_type ;
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typedef raw_type& reference_const_type ;
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typedef raw_type& reference_type ;
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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typedef BOOST_DEDUCED_TYPENAME remove_const<raw_type>::type&& rval_reference_type ;
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typedef raw_type& reference_type_of_temporary_wrapper;
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static reference_type move(reference_type r) { return r; }
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#endif
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typedef raw_type* pointer_const_type ;
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typedef raw_type* pointer_type ;
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typedef raw_type& argument_type ;
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} ;
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template <class To, class From>
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void prevent_binding_rvalue_ref_to_optional_lvalue_ref()
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{
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#ifndef BOOST_OPTIONAL_CONFIG_ALLOW_BINDING_TO_RVALUES
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BOOST_STATIC_ASSERT_MSG(
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!boost::is_lvalue_reference<To>::value || !boost::is_rvalue_reference<From>::value,
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"binding rvalue references to optional lvalue references is disallowed");
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#endif
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}
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struct optional_tag {} ;
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template<class T>
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class optional_base : public optional_tag
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{
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private :
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typedef
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#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
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BOOST_DEDUCED_TYPENAME
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#endif
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::boost::detail::make_reference_content<T>::type internal_type ;
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typedef aligned_storage<internal_type> storage_type ;
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typedef types_when_isnt_ref<T> types_when_not_ref ;
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typedef types_when_is_ref<T> types_when_ref ;
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typedef optional_base<T> this_type ;
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protected :
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typedef T value_type ;
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typedef mpl::true_ is_reference_tag ;
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typedef mpl::false_ is_not_reference_tag ;
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typedef BOOST_DEDUCED_TYPENAME is_reference<T>::type is_reference_predicate ;
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public:
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typedef BOOST_DEDUCED_TYPENAME mpl::if_<is_reference_predicate,types_when_ref,types_when_not_ref>::type types ;
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protected:
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typedef BOOST_DEDUCED_TYPENAME types::reference_type reference_type ;
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typedef BOOST_DEDUCED_TYPENAME types::reference_const_type reference_const_type ;
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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typedef BOOST_DEDUCED_TYPENAME types::rval_reference_type rval_reference_type ;
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typedef BOOST_DEDUCED_TYPENAME types::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ;
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#endif
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typedef BOOST_DEDUCED_TYPENAME types::pointer_type pointer_type ;
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typedef BOOST_DEDUCED_TYPENAME types::pointer_const_type pointer_const_type ;
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typedef BOOST_DEDUCED_TYPENAME types::argument_type argument_type ;
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// Creates an optional<T> uninitialized.
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// No-throw
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optional_base()
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:
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m_initialized(false) {}
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// Creates an optional<T> uninitialized.
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// No-throw
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optional_base ( none_t )
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:
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m_initialized(false) {}
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// Creates an optional<T> initialized with 'val'.
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// Can throw if T::T(T const&) does
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optional_base ( argument_type val )
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:
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m_initialized(false)
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{
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construct(val);
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// move-construct an optional<T> initialized from an rvalue-ref to 'val'.
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// Can throw if T::T(T&&) does
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optional_base ( rval_reference_type val )
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:
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m_initialized(false)
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{
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construct( boost::move(val) );
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}
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#endif
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// Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialzed optional<T>.
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// Can throw if T::T(T const&) does
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optional_base ( bool cond, argument_type val )
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:
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m_initialized(false)
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{
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if ( cond )
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construct(val);
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}
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// Creates a deep copy of another optional<T>
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// Can throw if T::T(T const&) does
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optional_base ( optional_base const& rhs )
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:
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m_initialized(false)
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{
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if ( rhs.is_initialized() )
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construct(rhs.get_impl());
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Creates a deep move of another optional<T>
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// Can throw if T::T(T&&) does
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optional_base ( optional_base&& rhs )
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:
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m_initialized(false)
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{
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if ( rhs.is_initialized() )
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construct( boost::move(rhs.get_impl()) );
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}
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#endif
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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template<class Expr, class PtrExpr>
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explicit optional_base ( Expr&& expr, PtrExpr const* tag )
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:
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m_initialized(false)
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{
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construct(boost::forward<Expr>(expr),tag);
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}
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#else
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// This is used for both converting and in-place constructions.
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// Derived classes use the 'tag' to select the appropriate
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// implementation (the correct 'construct()' overload)
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template<class Expr>
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explicit optional_base ( Expr const& expr, Expr const* tag )
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:
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m_initialized(false)
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{
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construct(expr,tag);
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}
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#endif
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// No-throw (assuming T::~T() doesn't)
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~optional_base() { destroy() ; }
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// Assigns from another optional<T> (deep-copies the rhs value)
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void assign ( optional_base const& rhs )
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{
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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assign_value(rhs.get_impl(), is_reference_predicate() );
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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construct(rhs.get_impl());
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}
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Assigns from another optional<T> (deep-moves the rhs value)
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void assign ( optional_base&& rhs )
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{
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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assign_value(boost::move(rhs.get_impl()), is_reference_predicate() );
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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construct(boost::move(rhs.get_impl()));
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}
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}
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#endif
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// Assigns from another _convertible_ optional<U> (deep-copies the rhs value)
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template<class U>
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void assign ( optional<U> const& rhs )
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{
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES
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assign_value(rhs.get(), is_reference_predicate() );
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#else
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assign_value(static_cast<value_type>(rhs.get()), is_reference_predicate() );
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#endif
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES
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construct(rhs.get());
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#else
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construct(static_cast<value_type>(rhs.get()));
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#endif
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}
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// move-assigns from another _convertible_ optional<U> (deep-moves from the rhs value)
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template<class U>
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void assign ( optional<U>&& rhs )
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{
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typedef BOOST_DEDUCED_TYPENAME optional<U>::rval_reference_type ref_type;
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if (is_initialized())
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{
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if ( rhs.is_initialized() )
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assign_value(static_cast<ref_type>(rhs.get()), is_reference_predicate() );
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else destroy();
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}
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else
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{
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if ( rhs.is_initialized() )
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construct(static_cast<ref_type>(rhs.get()));
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}
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}
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#endif
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// Assigns from a T (deep-copies the rhs value)
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void assign ( argument_type val )
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{
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if (is_initialized())
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assign_value(val, is_reference_predicate() );
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else construct(val);
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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// Assigns from a T (deep-moves the rhs value)
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void assign ( rval_reference_type val )
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{
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if (is_initialized())
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assign_value( boost::move(val), is_reference_predicate() );
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else construct( boost::move(val) );
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}
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#endif
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// Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED
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// No-throw (assuming T::~T() doesn't)
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void assign ( none_t ) BOOST_NOEXCEPT { destroy(); }
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#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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template<class Expr, class ExprPtr>
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void assign_expr ( Expr&& expr, ExprPtr const* tag )
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{
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if (is_initialized())
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assign_expr_to_initialized(boost::forward<Expr>(expr),tag);
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else construct(boost::forward<Expr>(expr),tag);
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}
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#else
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template<class Expr>
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void assign_expr ( Expr const& expr, Expr const* tag )
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{
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if (is_initialized())
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assign_expr_to_initialized(expr,tag);
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else construct(expr,tag);
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}
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#endif
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#endif
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public :
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// **DEPPRECATED** Destroys the current value, if any, leaving this UNINITIALIZED
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// No-throw (assuming T::~T() doesn't)
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void reset() BOOST_NOEXCEPT { destroy(); }
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// **DEPPRECATED** Replaces the current value -if any- with 'val'
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void reset ( argument_type val ) { assign(val); }
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// Returns a pointer to the value if this is initialized, otherwise,
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// returns NULL.
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// No-throw
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pointer_const_type get_ptr() const { return m_initialized ? get_ptr_impl() : 0 ; }
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pointer_type get_ptr() { return m_initialized ? get_ptr_impl() : 0 ; }
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bool is_initialized() const { return m_initialized ; }
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protected :
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void construct ( argument_type val )
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{
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::new (m_storage.address()) internal_type(val) ;
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m_initialized = true ;
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}
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#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
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void construct ( rval_reference_type val )
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{
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::new (m_storage.address()) internal_type( types::move(val) ) ;
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m_initialized = true ;
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}
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#endif
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#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
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// Constructs in-place
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// upon exception *this is always uninitialized
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template<class... Args>
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void emplace_assign ( Args&&... args )
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{
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destroy();
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||
|
|
::new (m_storage.address()) internal_type( boost::forward<Args>(args)... );
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
|
||
|
|
template<class Arg>
|
||
|
|
void emplace_assign ( Arg&& arg )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
::new (m_storage.address()) internal_type( boost::forward<Arg>(arg) );
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
void emplace_assign ()
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
::new (m_storage.address()) internal_type();
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
template<class Arg>
|
||
|
|
void emplace_assign ( const Arg& arg )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
::new (m_storage.address()) internal_type( arg );
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class Arg>
|
||
|
|
void emplace_assign ( Arg& arg )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
::new (m_storage.address()) internal_type( arg );
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
void emplace_assign ()
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
::new (m_storage.address()) internal_type();
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Constructs in-place using the given factory
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr&& factory, in_place_factory_base const* )
|
||
|
|
{
|
||
|
|
BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
|
||
|
|
boost_optional_detail::construct<value_type>(factory, m_storage.address());
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Constructs in-place using the given typed factory
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr&& factory, typed_in_place_factory_base const* )
|
||
|
|
{
|
||
|
|
BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
|
||
|
|
factory.apply(m_storage.address()) ;
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class Expr>
|
||
|
|
void assign_expr_to_initialized ( Expr&& factory, in_place_factory_base const* tag )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
construct(factory,tag);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Constructs in-place using the given typed factory
|
||
|
|
template<class Expr>
|
||
|
|
void assign_expr_to_initialized ( Expr&& factory, typed_in_place_factory_base const* tag )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
construct(factory,tag);
|
||
|
|
}
|
||
|
|
|
||
|
|
#else
|
||
|
|
// Constructs in-place using the given factory
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr const& factory, in_place_factory_base const* )
|
||
|
|
{
|
||
|
|
BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
|
||
|
|
boost_optional_detail::construct<value_type>(factory, m_storage.address());
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Constructs in-place using the given typed factory
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr const& factory, typed_in_place_factory_base const* )
|
||
|
|
{
|
||
|
|
BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ;
|
||
|
|
factory.apply(m_storage.address()) ;
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class Expr>
|
||
|
|
void assign_expr_to_initialized ( Expr const& factory, in_place_factory_base const* tag )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
construct(factory,tag);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Constructs in-place using the given typed factory
|
||
|
|
template<class Expr>
|
||
|
|
void assign_expr_to_initialized ( Expr const& factory, typed_in_place_factory_base const* tag )
|
||
|
|
{
|
||
|
|
destroy();
|
||
|
|
construct(factory,tag);
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Constructs using any expression implicitly convertible to the single argument
|
||
|
|
// of a one-argument T constructor.
|
||
|
|
// Converting constructions of optional<T> from optional<U> uses this function with
|
||
|
|
// 'Expr' being of type 'U' and relying on a converting constructor of T from U.
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr&& expr, void const* )
|
||
|
|
{
|
||
|
|
new (m_storage.address()) internal_type(boost::forward<Expr>(expr)) ;
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Assigns using a form any expression implicitly convertible to the single argument
|
||
|
|
// of a T's assignment operator.
|
||
|
|
// Converting assignments of optional<T> from optional<U> uses this function with
|
||
|
|
// 'Expr' being of type 'U' and relying on a converting assignment of T from U.
|
||
|
|
template<class Expr>
|
||
|
|
void assign_expr_to_initialized ( Expr&& expr, void const* )
|
||
|
|
{
|
||
|
|
assign_value(boost::forward<Expr>(expr), is_reference_predicate());
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
// Constructs using any expression implicitly convertible to the single argument
|
||
|
|
// of a one-argument T constructor.
|
||
|
|
// Converting constructions of optional<T> from optional<U> uses this function with
|
||
|
|
// 'Expr' being of type 'U' and relying on a converting constructor of T from U.
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr const& expr, void const* )
|
||
|
|
{
|
||
|
|
new (m_storage.address()) internal_type(expr) ;
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Assigns using a form any expression implicitly convertible to the single argument
|
||
|
|
// of a T's assignment operator.
|
||
|
|
// Converting assignments of optional<T> from optional<U> uses this function with
|
||
|
|
// 'Expr' being of type 'U' and relying on a converting assignment of T from U.
|
||
|
|
template<class Expr>
|
||
|
|
void assign_expr_to_initialized ( Expr const& expr, void const* )
|
||
|
|
{
|
||
|
|
assign_value(expr, is_reference_predicate());
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION
|
||
|
|
// BCB5.64 (and probably lower versions) workaround.
|
||
|
|
// The in-place factories are supported by means of catch-all constructors
|
||
|
|
// and assignment operators (the functions are parameterized in terms of
|
||
|
|
// an arbitrary 'Expr' type)
|
||
|
|
// This compiler incorrectly resolves the overload set and sinks optional<T> and optional<U>
|
||
|
|
// to the 'Expr'-taking functions even though explicit overloads are present for them.
|
||
|
|
// Thus, the following overload is needed to properly handle the case when the 'lhs'
|
||
|
|
// is another optional.
|
||
|
|
//
|
||
|
|
// For VC<=70 compilers this workaround dosen't work becasue the comnpiler issues and error
|
||
|
|
// instead of choosing the wrong overload
|
||
|
|
//
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>)
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr&& expr, optional_tag const* )
|
||
|
|
{
|
||
|
|
if ( expr.is_initialized() )
|
||
|
|
{
|
||
|
|
// An exception can be thrown here.
|
||
|
|
// It it happens, THIS will be left uninitialized.
|
||
|
|
new (m_storage.address()) internal_type(types::move(expr.get())) ;
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
// Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>)
|
||
|
|
template<class Expr>
|
||
|
|
void construct ( Expr const& expr, optional_tag const* )
|
||
|
|
{
|
||
|
|
if ( expr.is_initialized() )
|
||
|
|
{
|
||
|
|
// An exception can be thrown here.
|
||
|
|
// It it happens, THIS will be left uninitialized.
|
||
|
|
new (m_storage.address()) internal_type(expr.get()) ;
|
||
|
|
m_initialized = true ;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
#endif // defined BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION
|
||
|
|
|
||
|
|
void assign_value ( argument_type val, is_not_reference_tag ) { get_impl() = val; }
|
||
|
|
void assign_value ( argument_type val, is_reference_tag ) { construct(val); }
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
void assign_value ( rval_reference_type val, is_not_reference_tag ) { get_impl() = static_cast<rval_reference_type>(val); }
|
||
|
|
void assign_value ( rval_reference_type val, is_reference_tag ) { construct( static_cast<rval_reference_type>(val) ); }
|
||
|
|
#endif
|
||
|
|
|
||
|
|
void destroy()
|
||
|
|
{
|
||
|
|
if ( m_initialized )
|
||
|
|
destroy_impl(is_reference_predicate()) ;
|
||
|
|
}
|
||
|
|
|
||
|
|
reference_const_type get_impl() const { return dereference(get_object(), is_reference_predicate() ) ; }
|
||
|
|
reference_type get_impl() { return dereference(get_object(), is_reference_predicate() ) ; }
|
||
|
|
|
||
|
|
pointer_const_type get_ptr_impl() const { return cast_ptr(get_object(), is_reference_predicate() ) ; }
|
||
|
|
pointer_type get_ptr_impl() { return cast_ptr(get_object(), is_reference_predicate() ) ; }
|
||
|
|
|
||
|
|
private :
|
||
|
|
|
||
|
|
// internal_type can be either T or reference_content<T>
|
||
|
|
#if defined(BOOST_OPTIONAL_DETAIL_USE_ATTRIBUTE_MAY_ALIAS)
|
||
|
|
// This workaround is supposed to silence GCC warnings about broken strict aliasing rules
|
||
|
|
internal_type const* get_object() const
|
||
|
|
{
|
||
|
|
union { void const* ap_pvoid; internal_type const* as_ptype; } caster = { m_storage.address() };
|
||
|
|
return caster.as_ptype;
|
||
|
|
}
|
||
|
|
internal_type * get_object()
|
||
|
|
{
|
||
|
|
union { void* ap_pvoid; internal_type* as_ptype; } caster = { m_storage.address() };
|
||
|
|
return caster.as_ptype;
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
internal_type const* get_object() const { return static_cast<internal_type const*>(m_storage.address()); }
|
||
|
|
internal_type * get_object() { return static_cast<internal_type *> (m_storage.address()); }
|
||
|
|
#endif
|
||
|
|
|
||
|
|
// reference_content<T> lacks an implicit conversion to T&, so the following is needed to obtain a proper reference.
|
||
|
|
reference_const_type dereference( internal_type const* p, is_not_reference_tag ) const { return *p ; }
|
||
|
|
reference_type dereference( internal_type* p, is_not_reference_tag ) { return *p ; }
|
||
|
|
reference_const_type dereference( internal_type const* p, is_reference_tag ) const { return p->get() ; }
|
||
|
|
reference_type dereference( internal_type* p, is_reference_tag ) { return p->get() ; }
|
||
|
|
|
||
|
|
#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581))
|
||
|
|
void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->internal_type::~internal_type() ; m_initialized = false ; }
|
||
|
|
#else
|
||
|
|
void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->~T() ; m_initialized = false ; }
|
||
|
|
#endif
|
||
|
|
|
||
|
|
void destroy_impl ( is_reference_tag ) { m_initialized = false ; }
|
||
|
|
|
||
|
|
// If T is of reference type, trying to get a pointer to the held value must result in a compile-time error.
|
||
|
|
// Decent compilers should disallow conversions from reference_content<T>* to T*, but just in case,
|
||
|
|
// the following olverloads are used to filter out the case and guarantee an error in case of T being a reference.
|
||
|
|
pointer_const_type cast_ptr( internal_type const* p, is_not_reference_tag ) const { return p ; }
|
||
|
|
pointer_type cast_ptr( internal_type * p, is_not_reference_tag ) { return p ; }
|
||
|
|
pointer_const_type cast_ptr( internal_type const* p, is_reference_tag ) const { return &p->get() ; }
|
||
|
|
pointer_type cast_ptr( internal_type * p, is_reference_tag ) { return &p->get() ; }
|
||
|
|
|
||
|
|
bool m_initialized ;
|
||
|
|
storage_type m_storage ;
|
||
|
|
} ;
|
||
|
|
|
||
|
|
} // namespace optional_detail
|
||
|
|
|
||
|
|
template<class T>
|
||
|
|
class optional : public optional_detail::optional_base<T>
|
||
|
|
{
|
||
|
|
typedef optional_detail::optional_base<T> base ;
|
||
|
|
|
||
|
|
public :
|
||
|
|
|
||
|
|
typedef optional<T> this_type ;
|
||
|
|
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::value_type value_type ;
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::reference_type reference_type ;
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::reference_const_type reference_const_type ;
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::rval_reference_type rval_reference_type ;
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ;
|
||
|
|
#endif
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::pointer_type pointer_type ;
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::pointer_const_type pointer_const_type ;
|
||
|
|
typedef BOOST_DEDUCED_TYPENAME base::argument_type argument_type ;
|
||
|
|
|
||
|
|
// Creates an optional<T> uninitialized.
|
||
|
|
// No-throw
|
||
|
|
optional() BOOST_NOEXCEPT : base() {}
|
||
|
|
|
||
|
|
// Creates an optional<T> uninitialized.
|
||
|
|
// No-throw
|
||
|
|
optional( none_t none_ ) BOOST_NOEXCEPT : base(none_) {}
|
||
|
|
|
||
|
|
// Creates an optional<T> initialized with 'val'.
|
||
|
|
// Can throw if T::T(T const&) does
|
||
|
|
optional ( argument_type val ) : base(val) {}
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Creates an optional<T> initialized with 'move(val)'.
|
||
|
|
// Can throw if T::T(T &&) does
|
||
|
|
optional ( rval_reference_type val ) : base( boost::forward<T>(val) )
|
||
|
|
{optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, rval_reference_type>();}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
// Creates an optional<T> initialized with 'val' IFF cond is true, otherwise creates an uninitialized optional.
|
||
|
|
// Can throw if T::T(T const&) does
|
||
|
|
optional ( bool cond, argument_type val ) : base(cond,val) {}
|
||
|
|
|
||
|
|
// NOTE: MSVC needs templated versions first
|
||
|
|
|
||
|
|
// Creates a deep copy of another convertible optional<U>
|
||
|
|
// Requires a valid conversion from U to T.
|
||
|
|
// Can throw if T::T(U const&) does
|
||
|
|
template<class U>
|
||
|
|
explicit optional ( optional<U> const& rhs )
|
||
|
|
:
|
||
|
|
base()
|
||
|
|
{
|
||
|
|
if ( rhs.is_initialized() )
|
||
|
|
this->construct(rhs.get());
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Creates a deep move of another convertible optional<U>
|
||
|
|
// Requires a valid conversion from U to T.
|
||
|
|
// Can throw if T::T(U&&) does
|
||
|
|
template<class U>
|
||
|
|
explicit optional ( optional<U> && rhs )
|
||
|
|
:
|
||
|
|
base()
|
||
|
|
{
|
||
|
|
if ( rhs.is_initialized() )
|
||
|
|
this->construct( boost::move(rhs.get()) );
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
|
||
|
|
// Creates an optional<T> with an expression which can be either
|
||
|
|
// (a) An instance of InPlaceFactory (i.e. in_place(a,b,...,n);
|
||
|
|
// (b) An instance of TypedInPlaceFactory ( i.e. in_place<T>(a,b,...,n);
|
||
|
|
// (c) Any expression implicitly convertible to the single type
|
||
|
|
// of a one-argument T's constructor.
|
||
|
|
// (d*) Weak compilers (BCB) might also resolved Expr as optional<T> and optional<U>
|
||
|
|
// even though explicit overloads are present for these.
|
||
|
|
// Depending on the above some T ctor is called.
|
||
|
|
// Can throw if the resolved T ctor throws.
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
|
||
|
|
|
||
|
|
template<class Expr>
|
||
|
|
explicit optional ( Expr&& expr,
|
||
|
|
BOOST_DEDUCED_TYPENAME boost::disable_if_c<
|
||
|
|
(boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value) ||
|
||
|
|
boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value >::type* = 0
|
||
|
|
)
|
||
|
|
: base(boost::forward<Expr>(expr),boost::addressof(expr))
|
||
|
|
{optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>();}
|
||
|
|
|
||
|
|
#else
|
||
|
|
template<class Expr>
|
||
|
|
explicit optional ( Expr const& expr ) : base(expr,boost::addressof(expr)) {}
|
||
|
|
#endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
#endif // !defined BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
|
||
|
|
|
||
|
|
// Creates a deep copy of another optional<T>
|
||
|
|
// Can throw if T::T(T const&) does
|
||
|
|
optional ( optional const& rhs ) : base( static_cast<base const&>(rhs) ) {}
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Creates a deep move of another optional<T>
|
||
|
|
// Can throw if T::T(T&&) does
|
||
|
|
optional ( optional && rhs )
|
||
|
|
BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value)
|
||
|
|
: base( boost::move(rhs) )
|
||
|
|
{}
|
||
|
|
|
||
|
|
#endif
|
||
|
|
// No-throw (assuming T::~T() doesn't)
|
||
|
|
~optional() {}
|
||
|
|
|
||
|
|
#if !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION)
|
||
|
|
// Assigns from an expression. See corresponding constructor.
|
||
|
|
// Basic Guarantee: If the resolved T ctor throws, this is left UNINITIALIZED
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
|
||
|
|
template<class Expr>
|
||
|
|
BOOST_DEDUCED_TYPENAME boost::disable_if_c<
|
||
|
|
boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type>::value ||
|
||
|
|
boost::is_same<BOOST_DEDUCED_TYPENAME boost::decay<Expr>::type, none_t>::value,
|
||
|
|
optional&
|
||
|
|
>::type
|
||
|
|
operator= ( Expr&& expr )
|
||
|
|
{
|
||
|
|
optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, Expr&&>();
|
||
|
|
this->assign_expr(boost::forward<Expr>(expr),boost::addressof(expr));
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
|
||
|
|
#else
|
||
|
|
template<class Expr>
|
||
|
|
optional& operator= ( Expr const& expr )
|
||
|
|
{
|
||
|
|
this->assign_expr(expr,boost::addressof(expr));
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
#endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
#endif // !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION)
|
||
|
|
|
||
|
|
// Copy-assigns from another convertible optional<U> (converts && deep-copies the rhs value)
|
||
|
|
// Requires a valid conversion from U to T.
|
||
|
|
// Basic Guarantee: If T::T( U const& ) throws, this is left UNINITIALIZED
|
||
|
|
template<class U>
|
||
|
|
optional& operator= ( optional<U> const& rhs )
|
||
|
|
{
|
||
|
|
this->assign(rhs);
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Move-assigns from another convertible optional<U> (converts && deep-moves the rhs value)
|
||
|
|
// Requires a valid conversion from U to T.
|
||
|
|
// Basic Guarantee: If T::T( U && ) throws, this is left UNINITIALIZED
|
||
|
|
template<class U>
|
||
|
|
optional& operator= ( optional<U> && rhs )
|
||
|
|
{
|
||
|
|
this->assign(boost::move(rhs));
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
// Assigns from another optional<T> (deep-copies the rhs value)
|
||
|
|
// Basic Guarantee: If T::T( T const& ) throws, this is left UNINITIALIZED
|
||
|
|
// (NOTE: On BCB, this operator is not actually called and left is left UNMODIFIED in case of a throw)
|
||
|
|
optional& operator= ( optional const& rhs )
|
||
|
|
{
|
||
|
|
this->assign( static_cast<base const&>(rhs) ) ;
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Assigns from another optional<T> (deep-moves the rhs value)
|
||
|
|
optional& operator= ( optional && rhs )
|
||
|
|
BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value)
|
||
|
|
{
|
||
|
|
this->assign( static_cast<base &&>(rhs) ) ;
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
// Assigns from a T (deep-copies the rhs value)
|
||
|
|
// Basic Guarantee: If T::( T const& ) throws, this is left UNINITIALIZED
|
||
|
|
optional& operator= ( argument_type val )
|
||
|
|
{
|
||
|
|
this->assign( val ) ;
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
// Assigns from a T (deep-moves the rhs value)
|
||
|
|
optional& operator= ( rval_reference_type val )
|
||
|
|
{
|
||
|
|
optional_detail::prevent_binding_rvalue_ref_to_optional_lvalue_ref<T, rval_reference_type>();
|
||
|
|
this->assign( boost::move(val) ) ;
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
// Assigns from a "none"
|
||
|
|
// Which destroys the current value, if any, leaving this UNINITIALIZED
|
||
|
|
// No-throw (assuming T::~T() doesn't)
|
||
|
|
optional& operator= ( none_t none_ ) BOOST_NOEXCEPT
|
||
|
|
{
|
||
|
|
this->assign( none_ ) ;
|
||
|
|
return *this ;
|
||
|
|
}
|
||
|
|
|
||
|
|
#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
|
||
|
|
// Constructs in-place
|
||
|
|
// upon exception *this is always uninitialized
|
||
|
|
template<class... Args>
|
||
|
|
void emplace ( Args&&... args )
|
||
|
|
{
|
||
|
|
this->emplace_assign( boost::forward<Args>(args)... );
|
||
|
|
}
|
||
|
|
#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
|
||
|
|
template<class Arg>
|
||
|
|
void emplace ( Arg&& arg )
|
||
|
|
{
|
||
|
|
this->emplace_assign( boost::forward<Arg>(arg) );
|
||
|
|
}
|
||
|
|
|
||
|
|
void emplace ()
|
||
|
|
{
|
||
|
|
this->emplace_assign();
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
template<class Arg>
|
||
|
|
void emplace ( const Arg& arg )
|
||
|
|
{
|
||
|
|
this->emplace_assign( arg );
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class Arg>
|
||
|
|
void emplace ( Arg& arg )
|
||
|
|
{
|
||
|
|
this->emplace_assign( arg );
|
||
|
|
}
|
||
|
|
|
||
|
|
void emplace ()
|
||
|
|
{
|
||
|
|
this->emplace_assign();
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
void swap( optional & arg )
|
||
|
|
BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value)
|
||
|
|
{
|
||
|
|
// allow for Koenig lookup
|
||
|
|
boost::swap(*this, arg);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// Returns a reference to the value if this is initialized, otherwise,
|
||
|
|
// the behaviour is UNDEFINED
|
||
|
|
// No-throw
|
||
|
|
reference_const_type get() const { BOOST_ASSERT(this->is_initialized()) ; return this->get_impl(); }
|
||
|
|
reference_type get() { BOOST_ASSERT(this->is_initialized()) ; return this->get_impl(); }
|
||
|
|
|
||
|
|
// Returns a copy of the value if this is initialized, 'v' otherwise
|
||
|
|
reference_const_type get_value_or ( reference_const_type v ) const { return this->is_initialized() ? get() : v ; }
|
||
|
|
reference_type get_value_or ( reference_type v ) { return this->is_initialized() ? get() : v ; }
|
||
|
|
|
||
|
|
// Returns a pointer to the value if this is initialized, otherwise,
|
||
|
|
// the behaviour is UNDEFINED
|
||
|
|
// No-throw
|
||
|
|
pointer_const_type operator->() const { BOOST_ASSERT(this->is_initialized()) ; return this->get_ptr_impl() ; }
|
||
|
|
pointer_type operator->() { BOOST_ASSERT(this->is_initialized()) ; return this->get_ptr_impl() ; }
|
||
|
|
|
||
|
|
// Returns a reference to the value if this is initialized, otherwise,
|
||
|
|
// the behaviour is UNDEFINED
|
||
|
|
// No-throw
|
||
|
|
#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
|
||
|
|
reference_const_type operator *() const& { return this->get() ; }
|
||
|
|
reference_type operator *() & { return this->get() ; }
|
||
|
|
reference_type_of_temporary_wrapper operator *() && { return base::types::move(this->get()) ; }
|
||
|
|
#else
|
||
|
|
reference_const_type operator *() const { return this->get() ; }
|
||
|
|
reference_type operator *() { return this->get() ; }
|
||
|
|
#endif // !defined BOOST_NO_CXX11_REF_QUALIFIERS
|
||
|
|
|
||
|
|
#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
|
||
|
|
reference_const_type value() const&
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return this->get() ;
|
||
|
|
else
|
||
|
|
throw_exception(bad_optional_access());
|
||
|
|
}
|
||
|
|
|
||
|
|
reference_type value() &
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return this->get() ;
|
||
|
|
else
|
||
|
|
throw_exception(bad_optional_access());
|
||
|
|
}
|
||
|
|
|
||
|
|
reference_type_of_temporary_wrapper value() &&
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return base::types::move(this->get()) ;
|
||
|
|
else
|
||
|
|
throw_exception(bad_optional_access());
|
||
|
|
}
|
||
|
|
|
||
|
|
#else
|
||
|
|
reference_const_type value() const
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return this->get() ;
|
||
|
|
else
|
||
|
|
throw_exception(bad_optional_access());
|
||
|
|
}
|
||
|
|
|
||
|
|
reference_type value()
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return this->get() ;
|
||
|
|
else
|
||
|
|
throw_exception(bad_optional_access());
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
|
||
|
|
template <class U>
|
||
|
|
value_type value_or ( U&& v ) const&
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return get();
|
||
|
|
else
|
||
|
|
return boost::forward<U>(v);
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class U>
|
||
|
|
value_type value_or ( U&& v ) &&
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return base::types::move(get());
|
||
|
|
else
|
||
|
|
return boost::forward<U>(v);
|
||
|
|
}
|
||
|
|
#elif !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
|
||
|
|
template <class U>
|
||
|
|
value_type value_or ( U&& v ) const
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return get();
|
||
|
|
else
|
||
|
|
return boost::forward<U>(v);
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
template <class U>
|
||
|
|
value_type value_or ( U const& v ) const
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return get();
|
||
|
|
else
|
||
|
|
return v;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class U>
|
||
|
|
value_type value_or ( U& v ) const
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return get();
|
||
|
|
else
|
||
|
|
return v;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
|
||
|
|
template <typename F>
|
||
|
|
value_type value_or_eval ( F f ) const&
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return get();
|
||
|
|
else
|
||
|
|
return f();
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename F>
|
||
|
|
value_type value_or_eval ( F f ) &&
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return base::types::move(get());
|
||
|
|
else
|
||
|
|
return f();
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
template <typename F>
|
||
|
|
value_type value_or_eval ( F f ) const
|
||
|
|
{
|
||
|
|
if (this->is_initialized())
|
||
|
|
return get();
|
||
|
|
else
|
||
|
|
return f();
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
bool operator!() const BOOST_NOEXCEPT { return !this->is_initialized() ; }
|
||
|
|
|
||
|
|
BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()
|
||
|
|
} ;
|
||
|
|
|
||
|
|
} // namespace boost
|
||
|
|
|
||
|
|
|
||
|
|
#endif // header guard
|