Torque3D/Engine/source/console/fixedTuple.h

153 lines
5 KiB
C++

//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------
#ifndef _FIXEDTUPLE_H_
#define _FIXEDTUPLE_H_
/// @name Fixed-layout tuple definition
/// These structs and templates serve as a way to pass arguments from external
/// applications and into the T3D console system.
/// They work as std::tuple, but they ensure a standardized fixed memory
/// layout. Allowing for unmanaged calls with these tuples as the parameter
/// lists.
///
/// The implementation is from a SO solution:
/// https://codereview.stackexchange.com/a/52279
/// As out use-case is pretty simple, this code could probably be simplified by
/// stripping out a lot of extra functionality. But eh.
///
/// @{
template <typename ...Ts>
struct fixed_tuple;
template <typename T, typename ...Ts>
struct fixed_tuple<T, Ts...>
{
T first;
fixed_tuple<Ts...> rest;
fixed_tuple() = default;
template <class U, class...Us, class = typename ::std::enable_if<!::std::is_base_of<fixed_tuple, typename ::std::decay<U>::type>::value>::type>
fixed_tuple(U&& u, Us&&...tail) :
first(::std::forward<U>(u)),
rest(::std::forward<Us>(tail)...) {}
};
template <typename T>
struct fixed_tuple<T>
{
T first;
fixed_tuple() = default;
template <class U, class = typename ::std::enable_if<!::std::is_base_of<fixed_tuple, typename ::std::decay<U>::type>::value>::type>
fixed_tuple(U&& u) :
first(::std::forward<U>(u)) {}
};
template <>
struct fixed_tuple<> {};
template < ::std::size_t i, class T>
struct fixed_tuple_element;
template < ::std::size_t i, class T, class... Ts>
struct fixed_tuple_element<i, fixed_tuple<T, Ts...> >
: fixed_tuple_element<i - 1, fixed_tuple<Ts...> >
{};
template <class T, class... Ts>
struct fixed_tuple_element<0, fixed_tuple<T, Ts...> >
{
using type = T;
};
template < ::std::size_t i>
struct fixed_tuple_accessor
{
template <class... Ts>
static inline typename fixed_tuple_element<i, fixed_tuple<Ts...> >::type & get(fixed_tuple<Ts...> & t)
{
return fixed_tuple_accessor<i - 1>::get(t.rest);
}
template <class... Ts>
static inline const typename fixed_tuple_element<i, fixed_tuple<Ts...> >::type & get(const fixed_tuple<Ts...> & t)
{
return fixed_tuple_accessor<i - 1>::get(t.rest);
}
};
template <>
struct fixed_tuple_accessor<0>
{
template <class... Ts>
static inline typename fixed_tuple_element<0, fixed_tuple<Ts...> >::type & get(fixed_tuple<Ts...> & t)
{
return t.first;
}
template <class... Ts>
static inline const typename fixed_tuple_element<0, fixed_tuple<Ts...> >::type & get(const fixed_tuple<Ts...> & t)
{
return t.first;
}
};
template< typename T1, typename T2 >
struct fixed_tuple_mutator {};
template<typename... Tdest, typename... Tsrc>
struct fixed_tuple_mutator<void(Tdest...), void(Tsrc...)>
{
template<std::size_t I = 0>
static inline typename std::enable_if<I == sizeof...(Tsrc), void>::type
copy_r_t_l(fixed_tuple<Tsrc...>& src, fixed_tuple<Tdest...>& dest)
{ }
template<std::size_t I = 0>
static inline typename std::enable_if<I < sizeof...(Tsrc), void>::type
copy_r_t_l(fixed_tuple<Tsrc...>& src, fixed_tuple<Tdest...>& dest)
{
fixed_tuple_accessor<I + (sizeof...(Tdest)-sizeof...(Tsrc))>::get(dest) = fixed_tuple_accessor<I>::get(src);
copy_r_t_l<I + 1>(src, dest);
}
template<std::size_t I = 0>
static inline typename std::enable_if<I == sizeof...(Tsrc), void>::type
copy(std::tuple<Tsrc...>& src, fixed_tuple<Tdest...>& dest)
{ }
template<std::size_t I = 0>
static inline typename std::enable_if<I < sizeof...(Tsrc), void>::type
copy(std::tuple<Tsrc...>& src, fixed_tuple<Tdest...>& dest)
{
fixed_tuple_accessor<I>::get(dest) = std::get<I>(src);
copy<I + 1>(src, dest);
}
};
/// @}
#endif // !_FIXEDTUPLE_H_