// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) // (C) Copyright 2005-2007 Jonathan Turkanis // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) // See http://www.boost.org/libs/iostreams for documentation. // Recent changes to Boost.Optional involving assigment broke Boost.Iostreams, // in a way which could be remedied only by relying on the deprecated reset // functions; with VC6, even reset didn't work. Until this problem is // understood, Iostreams will use a private version of optional with a smart // pointer interface. #ifndef BOOST_IOSTREAMS_DETAIL_OPTIONAL_HPP_INCLUDED #define BOOST_IOSTREAMS_DETAIL_OPTIONAL_HPP_INCLUDED #if defined(_MSC_VER) && (_MSC_VER >= 1020) # pragma once #endif #include #include #include #include namespace boost { namespace iostreams { namespace detail { // Taken from . template class aligned_storage { // Borland ICEs if unnamed unions are used for this! union dummy_u { char data[ sizeof(T) ]; BOOST_DEDUCED_TYPENAME type_with_alignment< ::boost::alignment_of::value >::type aligner_; } dummy_ ; public: void const* address() const { return &dummy_.data[0]; } void * address() { return &dummy_.data[0]; } }; template class optional { public: typedef T element_type; optional() : initialized_(false) { } optional(const T& t) : initialized_(false) { reset(t); } ~optional() { reset(); } T& operator*() { BOOST_ASSERT(initialized_); return *static_cast(address()); } const T& operator*() const { BOOST_ASSERT(initialized_); return *static_cast(address()); } T* operator->() { BOOST_ASSERT(initialized_); return static_cast(address()); } const T* operator->() const { BOOST_ASSERT(initialized_); return static_cast(address()); } T* get() { BOOST_ASSERT(initialized_); return static_cast(address()); } const T* get() const { BOOST_ASSERT(initialized_); return static_cast(address()); } void reset() { if (initialized_) { #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) || \ BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600)) \ /**/ T* t = static_cast(address()); t->~T(); #else static_cast(address())->T::~T(); #endif initialized_ = false; } } void reset(const T& t) { reset(); new (address()) T(t); initialized_ = true; } private: optional(const optional&); optional& operator=(const optional&); void* address() { return &storage_; } const void* address() const { return &storage_; } aligned_storage storage_; bool initialized_; }; } } } // End namespaces detail, iostreams, boost. #endif // #ifndef BOOST_IOSTREAMS_DETAIL_OPTIONAL_HPP_INCLUDED