You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
2.0 KiB
57 lines
2.0 KiB
// RUN: %clang_cc1 -std=c++17 %s -verify
|
|
// expected-no-diagnostics
|
|
|
|
// This test attempts to ensure that the below template parameter pack
|
|
// splitting technique executes in linear time in the number of template
|
|
// parameters. The size of the list below is selected so as to execute
|
|
// relatively quickly on a "good" compiler and to time out otherwise.
|
|
|
|
template<typename...> struct TypeList;
|
|
|
|
namespace detail {
|
|
template<unsigned> using Unsigned = unsigned;
|
|
template<typename T, T ...N> using ListOfNUnsignedsImpl = TypeList<Unsigned<N>...>;
|
|
template<unsigned N> using ListOfNUnsigneds =
|
|
__make_integer_seq<ListOfNUnsignedsImpl, unsigned, N>;
|
|
|
|
template<typename T> struct TypeWrapper {
|
|
template<unsigned> using AsTemplate = T;
|
|
};
|
|
|
|
template<typename ...N> struct Splitter {
|
|
template<template<N> class ...L,
|
|
template<unsigned> class ...R> struct Split {
|
|
using Left = TypeList<L<0>...>;
|
|
using Right = TypeList<R<0>...>;
|
|
};
|
|
};
|
|
}
|
|
|
|
template<typename TypeList, unsigned N, typename = detail::ListOfNUnsigneds<N>>
|
|
struct SplitAtIndex;
|
|
|
|
template<typename ...T, unsigned N, typename ...NUnsigneds>
|
|
struct SplitAtIndex<TypeList<T...>, N, TypeList<NUnsigneds...>> :
|
|
detail::Splitter<NUnsigneds...>::
|
|
template Split<detail::TypeWrapper<T>::template AsTemplate...> {};
|
|
|
|
template<typename T, int N> struct Rep : Rep<typename Rep<T, N-1>::type, 1> {};
|
|
template<typename ...T> struct Rep<TypeList<T...>, 1> { typedef TypeList<T..., T...> type; };
|
|
|
|
using Ints = Rep<TypeList<int>, 14>::type;
|
|
|
|
template<typename T> extern int Size;
|
|
template<typename ...T> constexpr int Size<TypeList<T...>> = sizeof...(T);
|
|
|
|
using Left = SplitAtIndex<Ints, Size<Ints> / 2>::Left;
|
|
using Right = SplitAtIndex<Ints, Size<Ints> / 2>::Right;
|
|
static_assert(Size<Left> == 8192);
|
|
static_assert(Size<Right> == 8192);
|
|
|
|
template<typename L, typename R> struct Concat;
|
|
template<typename ...L, typename ...R> struct Concat<TypeList<L...>, TypeList<R...>> {
|
|
using type = TypeList<L..., R...>;
|
|
};
|
|
|
|
using Ints = Concat<Left, Right>::type;
|