123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111 |
- // Copyright Daniel Wallin, David Abrahams 2005.
- // Copyright Cromwell D. Enage 2017.
- // 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)
- #ifndef BOOST_PARAMETER_AUX_DEFAULT_HPP
- #define BOOST_PARAMETER_AUX_DEFAULT_HPP
- namespace boost { namespace parameter { namespace aux {
- // A wrapper for the default value passed by the user when resolving
- // the value of the parameter with the given Keyword
- template <typename Keyword, typename Value>
- struct default_
- {
- inline BOOST_CONSTEXPR default_(Value& x) : value(x)
- {
- }
- Value& value;
- };
- }}} // namespace boost::parameter::aux
- #include <boost/parameter/config.hpp>
- namespace boost { namespace parameter { namespace aux {
- // lazy_default -- A wrapper for the default value computation function
- // passed by the user when resolving the value of the parameter with the
- // given keyword.
- #if BOOST_WORKAROUND(__EDG_VERSION__, <= 300)
- // These compilers need a little extra help with overload resolution;
- // we have empty_arg_list's operator[] accept a base class
- // to make that overload less preferable.
- template <typename KW, typename DefaultComputer>
- struct lazy_default_base
- {
- inline BOOST_CONSTEXPR lazy_default_base(DefaultComputer& x)
- : compute_default(x)
- {
- }
- DefaultComputer& compute_default;
- };
- template <typename KW, typename DefaultComputer>
- struct lazy_default
- : ::boost::parameter::aux::lazy_default_base<KW,DefaultComputer>
- {
- inline BOOST_CONSTEXPR lazy_default(DefaultComputer& x)
- : ::boost::parameter::aux::lazy_default_base<KW,DefaultComputer>(x)
- {
- }
- };
- #else // !BOOST_WORKAROUND(__EDG_VERSION__, <= 300)
- template <typename KW, typename DefaultComputer>
- struct lazy_default
- {
- inline BOOST_CONSTEXPR lazy_default(DefaultComputer& x)
- : compute_default(x)
- {
- }
- DefaultComputer& compute_default;
- };
- #endif // EDG workarounds needed.
- }}} // namespace boost::parameter::aux
- #if BOOST_WORKAROUND(__EDG_VERSION__, <= 300)
- #define BOOST_PARAMETER_lazy_default_fallback \
- ::boost::parameter::aux::lazy_default_base
- /**/
- #else
- #define BOOST_PARAMETER_lazy_default_fallback \
- ::boost::parameter::aux::lazy_default
- /**/
- #endif
- #if defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING)
- #include <utility>
- namespace boost { namespace parameter { namespace aux {
- template <typename Keyword, typename Value>
- struct default_r_
- {
- inline BOOST_CONSTEXPR default_r_(Value&& x)
- : value(::std::forward<Value>(x))
- {
- }
- #if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
- // MSVC 2015 miscompiles moves for classes containing rvalue ref members
- // using the default generated move constructor
- // when moving into a function
- // https://github.com/boostorg/parameter/pull/109
- inline BOOST_CONSTEXPR default_r_(default_r_&& x)
- : value(::std::forward<Value>(x.value))
- {
- }
- #endif
- Value&& value;
- };
- }}} // namespace boost::parameter::aux
- #endif // BOOST_PARAMETER_HAS_PERFECT_FORWARDING
- #endif // include guard
|