williamr@2: //  (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
williamr@2: //  Use, modification and distribution are subject to the Boost Software License,
williamr@2: //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
williamr@2: //  http://www.boost.org/LICENSE_1_0.txt).
williamr@2: //
williamr@2: //  See http://www.boost.org/libs/utility for most recent version including documentation.
williamr@2: 
williamr@2: // call_traits: defines typedefs for function usage
williamr@2: // (see libs/utility/call_traits.htm)
williamr@2: 
williamr@2: /* Release notes:
williamr@2:    23rd July 2000:
williamr@2:       Fixed array specialization. (JM)
williamr@2:       Added Borland specific fixes for reference types
williamr@2:       (issue raised by Steve Cleary).
williamr@2: */
williamr@2: 
williamr@2: #ifndef BOOST_DETAIL_CALL_TRAITS_HPP
williamr@2: #define BOOST_DETAIL_CALL_TRAITS_HPP
williamr@2: 
williamr@2: #ifndef BOOST_CONFIG_HPP
williamr@2: #include <boost/config.hpp>
williamr@2: #endif
williamr@2: #include <cstddef>
williamr@2: 
williamr@2: #include <boost/type_traits/is_arithmetic.hpp>
williamr@2: #include <boost/type_traits/is_pointer.hpp>
williamr@2: #include <boost/detail/workaround.hpp>
williamr@2: 
williamr@2: namespace boost{
williamr@2: 
williamr@2: namespace detail{
williamr@2: 
williamr@2: template <typename T, bool small_>
williamr@2: struct ct_imp2
williamr@2: {
williamr@2:    typedef const T& param_type;
williamr@2: };
williamr@2: 
williamr@2: template <typename T>
williamr@2: struct ct_imp2<T, true>
williamr@2: {
williamr@2:    typedef const T param_type;
williamr@2: };
williamr@2: 
williamr@2: template <typename T, bool isp, bool b1>
williamr@2: struct ct_imp
williamr@2: {
williamr@2:    typedef const T& param_type;
williamr@2: };
williamr@2: 
williamr@2: template <typename T, bool isp>
williamr@2: struct ct_imp<T, isp, true>
williamr@2: {
williamr@2:    typedef typename ct_imp2<T, sizeof(T) <= sizeof(void*)>::param_type param_type;
williamr@2: };
williamr@2: 
williamr@2: template <typename T, bool b1>
williamr@2: struct ct_imp<T, true, b1>
williamr@2: {
williamr@2:    typedef const T param_type;
williamr@2: };
williamr@2: 
williamr@2: }
williamr@2: 
williamr@2: template <typename T>
williamr@2: struct call_traits
williamr@2: {
williamr@2: public:
williamr@2:    typedef T value_type;
williamr@2:    typedef T& reference;
williamr@2:    typedef const T& const_reference;
williamr@2:    //
williamr@2:    // C++ Builder workaround: we should be able to define a compile time
williamr@2:    // constant and pass that as a single template parameter to ct_imp<T,bool>,
williamr@2:    // however compiler bugs prevent this - instead pass three bool's to
williamr@2:    // ct_imp<T,bool,bool,bool> and add an extra partial specialisation
williamr@2:    // of ct_imp to handle the logic. (JM)
williamr@2:    typedef typename boost::detail::ct_imp<
williamr@2:       T,
williamr@2:       ::boost::is_pointer<T>::value,
williamr@2:       ::boost::is_arithmetic<T>::value
williamr@2:    >::param_type param_type;
williamr@2: };
williamr@2: 
williamr@2: template <typename T>
williamr@2: struct call_traits<T&>
williamr@2: {
williamr@2:    typedef T& value_type;
williamr@2:    typedef T& reference;
williamr@2:    typedef const T& const_reference;
williamr@2:    typedef T& param_type;  // hh removed const
williamr@2: };
williamr@2: 
williamr@2: #if BOOST_WORKAROUND( __BORLANDC__,  BOOST_TESTED_AT( 0x581 ) )
williamr@2: // these are illegal specialisations; cv-qualifies applied to
williamr@2: // references have no effect according to [8.3.2p1],
williamr@2: // C++ Builder requires them though as it treats cv-qualified
williamr@2: // references as distinct types...
williamr@2: template <typename T>
williamr@2: struct call_traits<T&const>
williamr@2: {
williamr@2:    typedef T& value_type;
williamr@2:    typedef T& reference;
williamr@2:    typedef const T& const_reference;
williamr@2:    typedef T& param_type;  // hh removed const
williamr@2: };
williamr@2: template <typename T>
williamr@2: struct call_traits<T&volatile>
williamr@2: {
williamr@2:    typedef T& value_type;
williamr@2:    typedef T& reference;
williamr@2:    typedef const T& const_reference;
williamr@2:    typedef T& param_type;  // hh removed const
williamr@2: };
williamr@2: template <typename T>
williamr@2: struct call_traits<T&const volatile>
williamr@2: {
williamr@2:    typedef T& value_type;
williamr@2:    typedef T& reference;
williamr@2:    typedef const T& const_reference;
williamr@2:    typedef T& param_type;  // hh removed const
williamr@2: };
williamr@2: 
williamr@2: template <typename T>
williamr@2: struct call_traits< T * >
williamr@2: {
williamr@2:    typedef T * value_type;
williamr@2:    typedef T * & reference;
williamr@2:    typedef T * const & const_reference;
williamr@2:    typedef T * const param_type;  // hh removed const
williamr@2: };
williamr@2: #endif
williamr@2: #if !defined(BOOST_NO_ARRAY_TYPE_SPECIALIZATIONS)
williamr@2: template <typename T, std::size_t N>
williamr@2: struct call_traits<T [N]>
williamr@2: {
williamr@2: private:
williamr@2:    typedef T array_type[N];
williamr@2: public:
williamr@2:    // degrades array to pointer:
williamr@2:    typedef const T* value_type;
williamr@2:    typedef array_type& reference;
williamr@2:    typedef const array_type& const_reference;
williamr@2:    typedef const T* const param_type;
williamr@2: };
williamr@2: 
williamr@2: template <typename T, std::size_t N>
williamr@2: struct call_traits<const T [N]>
williamr@2: {
williamr@2: private:
williamr@2:    typedef const T array_type[N];
williamr@2: public:
williamr@2:    // degrades array to pointer:
williamr@2:    typedef const T* value_type;
williamr@2:    typedef array_type& reference;
williamr@2:    typedef const array_type& const_reference;
williamr@2:    typedef const T* const param_type;
williamr@2: };
williamr@2: #endif
williamr@2: 
williamr@2: }
williamr@2: 
williamr@2: #endif // BOOST_DETAIL_CALL_TRAITS_HPP