EVOLUTION-MANAGER

Edit File: optional_trivially_copyable_base.hpp

// trivilally-copyable version of the storage

template<class T>
class tc_optional_base : public optional_tag
{
 private :

typedef tc_optional_base<T> this_type ;

protected :

typedef T value_type ;

protected:
    typedef T &       reference_type ;
    typedef T const&  reference_const_type ;
#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
    typedef T &&  rval_reference_type ;
    typedef T &&  reference_type_of_temporary_wrapper ;
#endif
    typedef T *         pointer_type ;
    typedef T const*    pointer_const_type ;
    typedef T const&    argument_type ;

tc_optional_base()
      :
      m_initialized(false) {}

tc_optional_base ( none_t )
      :
      m_initialized(false) {}

tc_optional_base ( init_value_tag, argument_type val )
      :
      m_initialized(true), m_storage(val) {}

tc_optional_base ( bool cond, argument_type val )
      :
      m_initialized(cond), m_storage(val) {}

// tc_optional_base ( tc_optional_base const& ) = default;

#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES

template<class Expr, class PtrExpr>
 explicit tc_optional_base ( Expr&& expr, PtrExpr const* tag )
 :
 m_initialized(false)
 {
 construct(boost::forward<Expr>(expr),tag);
 }

#else
 // This is used for both converting and in-place constructions.
 // Derived classes use the 'tag' to select the appropriate
 // implementation (the correct 'construct()' overload)
 template<class Expr>
 explicit tc_optional_base ( Expr const& expr, Expr const* tag )
 :
 m_initialized(false)
 {
 construct(expr,tag);
 }

#endif

// tc_optional_base& operator= ( tc_optional_base const& ) = default;
    // ~tc_optional_base() = default;

// Assigns from another optional<T> (deep-copies the rhs value)
 void assign ( tc_optional_base const& rhs ) 
 {
 *this = rhs;
 }

// Assigns from another _convertible_ optional (deep-copies the rhs value)
 template<class U>
 void assign ( optional const& rhs )
 {
 if ( rhs.is_initialized() )
#ifndef BOOST_OPTIONAL_CONFIG_RESTORE_ASSIGNMENT_OF_NONCONVERTIBLE_TYPES
 m_storage = rhs.get();
#else
 m_storage = static_cast<value_type>(rhs.get());
#endif
 
 m_initialized = rhs.is_initialized();
 }

#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 // move-assigns from another _convertible_ optional (deep-moves from the rhs value)
 template<class U>
 void assign ( optional&& rhs )
 {
 typedef BOOST_DEDUCED_TYPENAME optional::rval_reference_type ref_type;
 if ( rhs.is_initialized() )
 m_storage = static_cast<ref_type>(rhs.get());
 m_initialized = rhs.is_initialized();
 }
#endif
 
 void assign ( argument_type val )
 {
 construct(val);
 }

void assign ( none_t ) { destroy(); }

#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT

#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 template<class Expr, class ExprPtr>
 void assign_expr ( Expr&& expr, ExprPtr const* tag )
 {
 construct(boost::forward<Expr>(expr),tag);
 }
#else
 template<class Expr>
 void assign_expr ( Expr const& expr, Expr const* tag )
 {
 construct(expr,tag);
 }
#endif

#endif

public :

// Destroys the current value, if any, leaving this UNINITIALIZED
    // No-throw (assuming T::~T() doesn't)
    void reset() BOOST_NOEXCEPT { destroy(); }

// **DEPPRECATED** Replaces the current value -if any- with 'val'
    void reset ( argument_type val ) BOOST_NOEXCEPT { assign(val); }

// Returns a pointer to the value if this is initialized, otherwise,
    // returns NULL.
    // No-throw
    pointer_const_type get_ptr() const { return m_initialized ? get_ptr_impl() : 0 ; }
    pointer_type       get_ptr()       { return m_initialized ? get_ptr_impl() : 0 ; }

bool is_initialized() const { return m_initialized ; }

protected :

void construct ( argument_type val )
     {
       m_storage = val ;
       m_initialized = true ;
     }

#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 construct ( in_place_init_t, Args&&... args )
 {
 m_storage = value_type( boost::forward<Args>(args)... ) ;
 m_initialized = true ;
 }

template<class... Args>
 void emplace_assign ( Args&&... args )
 {
 construct(in_place_init, boost::forward<Args>(args)...);
 }
 
 template<class... Args>
 explicit tc_optional_base ( in_place_init_t, Args&&... args )
 :
 m_initialized(false)
 {
 construct(in_place_init, boost::forward<Args>(args)...);
 }
 
 template<class... Args>
 explicit tc_optional_base ( in_place_init_if_t, bool cond, Args&&... args )
 :
 m_initialized(false)
 {
 if ( cond )
 construct(in_place_init, boost::forward<Args>(args)...);
 }
#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
 template<class Arg>
 void construct ( in_place_init_t, Arg&& arg )
 {
 m_storage = value_type( boost::forward<Arg>(arg) );
 m_initialized = true ;
 }
 
 void construct ( in_place_init_t )
 {
 m_storage = value_type();
 m_initialized = true ;
 }
 
 template<class Arg>
 void emplace_assign ( Arg&& arg )
 {
 construct(in_place_init, boost::forward<Arg>(arg)) ;
 }
 
 void emplace_assign ()
 {
 construct(in_place_init) ;
 }
 
 template<class Arg>
 explicit tc_optional_base ( in_place_init_t, Arg&& arg )
 :
 m_initialized(false)
 {
 construct(in_place_init, boost::forward<Arg>(arg));
 }
 
 explicit tc_optional_base ( in_place_init_t )
 :
 m_initialized(false), m_storage() {}
 
 template<class Arg>
 explicit tc_optional_base ( in_place_init_if_t, bool cond, Arg&& arg )
 :
 m_initialized(false)
 {
 if ( cond )
 construct(in_place_init, boost::forward<Arg>(arg));
 }
 
 explicit tc_optional_base ( in_place_init_if_t, bool cond )
 :
 m_initialized(false)
 {
 if ( cond )
 construct(in_place_init);
 }

#else
 
 template<class Arg>
 void construct ( in_place_init_t, const Arg& arg )
 {
 m_storage = value_type( arg );
 m_initialized = true ;
 }
 
 template<class Arg>
 void construct ( in_place_init_t, Arg& arg )
 {
 m_storage = value_type( arg );
 m_initialized = true ;
 }
 
 void construct ( in_place_init_t )
 {
 m_storage = value_type();
 m_initialized = true ;
 }

template<class Arg>
 void emplace_assign ( const Arg& arg )
 {
 construct(in_place_init, arg);
 }
 
 template<class Arg>
 void emplace_assign ( Arg& arg )
 {
 construct(in_place_init, arg);
 }
 
 void emplace_assign ()
 {
 construct(in_place_init);
 }
 
 template<class Arg>
 explicit tc_optional_base ( in_place_init_t, const Arg& arg )
 : m_initialized(false)
 {
 construct(in_place_init, arg);
 }

template<class Arg>
 explicit tc_optional_base ( in_place_init_t, Arg& arg )
 : m_initialized(false)
 {
 construct(in_place_init, arg);
 }
 
 explicit tc_optional_base ( in_place_init_t )
 : m_initialized(false)
 {
 construct(in_place_init);
 }
 
 template<class Arg>
 explicit tc_optional_base ( in_place_init_if_t, bool cond, const Arg& arg )
 : m_initialized(false)
 {
 if ( cond )
 construct(in_place_init, arg);
 }
 
 template<class Arg>
 explicit tc_optional_base ( in_place_init_if_t, bool cond, Arg& arg )
 : m_initialized(false)
 {
 if ( cond )
 construct(in_place_init, arg);
 } 
 
 explicit tc_optional_base ( in_place_init_if_t, bool cond )
 : m_initialized(false)
 {
 if ( cond )
 construct(in_place_init);
 }
#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_optional_detail::construct<value_type>(factory, boost::addressof(m_storage));
 m_initialized = true ;
 }

// Constructs in-place using the given typed factory
 template<class Expr>
 void construct ( Expr&& factory, typed_in_place_factory_base const* )
 {
 factory.apply(boost::addressof(m_storage)) ;
 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_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* )
 {
 factory.apply(boost::addressof(m_storage)) ;
 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 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* )
 {
 m_storage = value_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 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) );
 }
#else
 // Constructs using any expression implicitly convertible to the single argument
 // of a one-argument T constructor.
 // Converting constructions of optional<T> from optional 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* )
 {
 m_storage = value_type(expr) ;
 m_initialized = true ;
 }

#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
 // 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 (but not tc_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.
 m_storage = value_type(boost::move(expr.get())) ;
 m_initialized = true ;
 }
 }
#else
 // Notice that 'Expr' will be optional<T> or optional (but not tc_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.
 m_storage = value_type(expr.get()) ;
 m_initialized = true ;
 }
 }
#endif
#endif // defined BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION

void assign_value ( argument_type val ) { m_storage = val; }
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 void assign_value ( rval_reference_type val ) { m_storage = static_cast<rval_reference_type>(val); }
#endif

void destroy()
    {
      m_initialized = false;
    }

reference_const_type get_impl() const { return m_storage ; }
    reference_type       get_impl()       { return m_storage ; }

pointer_const_type get_ptr_impl() const { return boost::addressof(m_storage); }
    pointer_type       get_ptr_impl()       { return boost::addressof(m_storage); }

private :

bool m_initialized ;
    T    m_storage ;
} ;