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| author | Jonathan Wakely <jwakely@redhat.com> | 2017-09-18 13:02:19 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2017-09-18 13:02:19 +0100 |
| commit | db624b3b4b3a15d06cef746f2db07a334d669084 (patch) | |
| tree | 77438da840f4806ce37a73f5a7d7d6db1aaf674c /libstdc++-v3/include | |
| parent | ec26ff5a012428ed864b679c7c171e2e7d917f76 (diff) | |
| download | gcc-db624b3b4b3a15d06cef746f2db07a334d669084.zip gcc-db624b3b4b3a15d06cef746f2db07a334d669084.tar.gz gcc-db624b3b4b3a15d06cef746f2db07a334d669084.tar.bz2 | |
Use built-in for std::make_integer_sequnce
* include/std/utility (_Itup_cat, _Make_integer_sequence): Remove.
(_Build_index_tuple, make_integer_sequence): Use built-in to generate
pack expansion.
From-SVN: r252923
Diffstat (limited to 'libstdc++-v3/include')
| -rw-r--r-- | libstdc++-v3/include/std/utility | 53 |
1 files changed, 19 insertions, 34 deletions
diff --git a/libstdc++-v3/include/std/utility b/libstdc++-v3/include/std/utility index c18bcb6..29a6260 100644 --- a/libstdc++-v3/include/std/utility +++ b/libstdc++-v3/include/std/utility @@ -267,32 +267,24 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // extract the elements in a tuple. template<size_t... _Indexes> struct _Index_tuple { }; - // Concatenates two _Index_tuples. - template<typename _Itup1, typename _Itup2> struct _Itup_cat; - - template<size_t... _Ind1, size_t... _Ind2> - struct _Itup_cat<_Index_tuple<_Ind1...>, _Index_tuple<_Ind2...>> - { - using __type = _Index_tuple<_Ind1..., (_Ind2 + sizeof...(_Ind1))...>; - }; +#ifdef __has_builtin +# if __has_builtin(__make_integer_seq) +# define _GLIBCXX_USE_MAKE_INTEGER_SEQ 1 +# endif +#endif // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>. template<size_t _Num> struct _Build_index_tuple - : _Itup_cat<typename _Build_index_tuple<_Num / 2>::__type, - typename _Build_index_tuple<_Num - _Num / 2>::__type> - { }; - - template<> - struct _Build_index_tuple<1> { - typedef _Index_tuple<0> __type; - }; +#if _GLIBCXX_USE_MAKE_INTEGER_SEQ + template<typename, size_t... _Indices> + using _IdxTuple = _Index_tuple<_Indices...>; - template<> - struct _Build_index_tuple<0> - { - typedef _Index_tuple<> __type; + using __type = __make_integer_seq<_IdxTuple, size_t, _Num>; +#else + using __type = _Index_tuple<__integer_pack(_Num)...>; +#endif }; #if __cplusplus > 201103L @@ -307,23 +299,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION static constexpr size_t size() { return sizeof...(_Idx); } }; - template<typename _Tp, _Tp _Num, - typename _ISeq = typename _Build_index_tuple<_Num>::__type> - struct _Make_integer_sequence; - - template<typename _Tp, _Tp _Num, size_t... _Idx> - struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>> - { - static_assert( _Num >= 0, - "Cannot make integer sequence of negative length" ); - - typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type; - }; - /// Alias template make_integer_sequence template<typename _Tp, _Tp _Num> using make_integer_sequence - = typename _Make_integer_sequence<_Tp, _Num>::__type; +#if _GLIBCXX_USE_MAKE_INTEGER_SEQ + = __make_integer_seq<integer_sequence, _Tp, _Num>; +#else + = integer_sequence<_Tp, __integer_pack(_Num)...>; +#endif + +#undef _GLIBCXX_USE_MAKE_INTEGER_SEQ /// Alias template index_sequence template<size_t... _Idx> |