155 lines
5.2 KiB
Plaintext
155 lines
5.2 KiB
Plaintext
/*
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* Copyright Andrey Semashev 2007 - 2013.
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* Distributed under the Boost Software License, Version 1.0.
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* (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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/*!
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* \file explicit_operator_bool.hpp
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* \author Andrey Semashev
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* \date 08.03.2009
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*
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* This header defines a compatibility macro that implements an unspecified
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* \c bool operator idiom, which is superseded with explicit conversion operators in
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* C++11.
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*/
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#ifndef BOOST_CORE_EXPLICIT_OPERATOR_BOOL_HPP
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#define BOOST_CORE_EXPLICIT_OPERATOR_BOOL_HPP
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#include <boost/config.hpp>
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#ifdef BOOST_HAS_PRAGMA_ONCE
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#pragma once
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#endif
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#if !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
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/*!
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* \brief The macro defines an explicit operator of conversion to \c bool
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*
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* The macro should be used inside the definition of a class that has to
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* support the conversion. The class should also implement <tt>operator!</tt>,
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* in terms of which the conversion operator will be implemented.
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*/
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#define BOOST_EXPLICIT_OPERATOR_BOOL()\
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BOOST_FORCEINLINE explicit operator bool () const\
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{\
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return !this->operator! ();\
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}
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/*!
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* \brief The macro defines a noexcept explicit operator of conversion to \c bool
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*
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* The macro should be used inside the definition of a class that has to
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* support the conversion. The class should also implement <tt>operator!</tt>,
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* in terms of which the conversion operator will be implemented.
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*/
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#define BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()\
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BOOST_FORCEINLINE explicit operator bool () const BOOST_NOEXCEPT\
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{\
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return !this->operator! ();\
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}
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/*!
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* \brief The macro defines a constexpr explicit operator of conversion to \c bool
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*
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* The macro should be used inside the definition of a class that has to
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* support the conversion. The class should also implement <tt>operator!</tt>,
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* in terms of which the conversion operator will be implemented.
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*/
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#define BOOST_CONSTEXPR_EXPLICIT_OPERATOR_BOOL()\
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BOOST_FORCEINLINE BOOST_CONSTEXPR explicit operator bool () const BOOST_NOEXCEPT\
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{\
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return !this->operator! ();\
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}
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#else // !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
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#if (defined(__SUNPRO_CC) && (__SUNPRO_CC <= 0x530)) && !defined(BOOST_NO_COMPILER_CONFIG)
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// Sun C++ 5.3 can't handle the safe_bool idiom, so don't use it
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#define BOOST_NO_UNSPECIFIED_BOOL
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#endif // (defined(__SUNPRO_CC) && (__SUNPRO_CC <= 0x530)) && !defined(BOOST_NO_COMPILER_CONFIG)
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#if !defined(BOOST_NO_UNSPECIFIED_BOOL)
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namespace boost {
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namespace detail {
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#if !defined(_MSC_VER) && !defined(__IBMCPP__)
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struct unspecified_bool
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{
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// NOTE TO THE USER: If you see this in error messages then you tried
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// to apply an unsupported operator on the object that supports
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// explicit conversion to bool.
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struct OPERATORS_NOT_ALLOWED;
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static void true_value(OPERATORS_NOT_ALLOWED*) {}
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};
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typedef void (*unspecified_bool_type)(unspecified_bool::OPERATORS_NOT_ALLOWED*);
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#else
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// MSVC and VACPP are too eager to convert pointer to function to void* even though they shouldn't
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struct unspecified_bool
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{
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// NOTE TO THE USER: If you see this in error messages then you tried
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// to apply an unsupported operator on the object that supports
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// explicit conversion to bool.
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struct OPERATORS_NOT_ALLOWED;
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void true_value(OPERATORS_NOT_ALLOWED*) {}
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};
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typedef void (unspecified_bool::*unspecified_bool_type)(unspecified_bool::OPERATORS_NOT_ALLOWED*);
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#endif
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} // namespace detail
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} // namespace boost
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#define BOOST_EXPLICIT_OPERATOR_BOOL()\
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BOOST_FORCEINLINE operator boost::detail::unspecified_bool_type () const\
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{\
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return (!this->operator! () ? &boost::detail::unspecified_bool::true_value : (boost::detail::unspecified_bool_type)0);\
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}
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#define BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()\
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BOOST_FORCEINLINE operator boost::detail::unspecified_bool_type () const BOOST_NOEXCEPT\
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{\
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return (!this->operator! () ? &boost::detail::unspecified_bool::true_value : (boost::detail::unspecified_bool_type)0);\
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}
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#define BOOST_CONSTEXPR_EXPLICIT_OPERATOR_BOOL()\
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BOOST_FORCEINLINE BOOST_CONSTEXPR operator boost::detail::unspecified_bool_type () const BOOST_NOEXCEPT\
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{\
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return (!this->operator! () ? &boost::detail::unspecified_bool::true_value : (boost::detail::unspecified_bool_type)0);\
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}
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#else // !defined(BOOST_NO_UNSPECIFIED_BOOL)
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#define BOOST_EXPLICIT_OPERATOR_BOOL()\
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BOOST_FORCEINLINE operator bool () const\
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{\
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return !this->operator! ();\
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}
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#define BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()\
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BOOST_FORCEINLINE operator bool () const BOOST_NOEXCEPT\
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{\
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return !this->operator! ();\
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}
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#define BOOST_CONSTEXPR_EXPLICIT_OPERATOR_BOOL()\
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BOOST_FORCEINLINE BOOST_CONSTEXPR operator bool () const BOOST_NOEXCEPT\
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{\
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return !this->operator! ();\
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}
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#endif // !defined(BOOST_NO_UNSPECIFIED_BOOL)
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#endif // !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
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#endif // BOOST_CORE_EXPLICIT_OPERATOR_BOOL_HPP
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