On 3/18/19 6:18 PM, Jonathan Wakely wrote:
On 17/03/19 22:54 -0400, Ed Smith-Rowland via libstdc++ wrote:Greetings,This patch implements C++20 p0202 - Add Constexpr Modifiers to Functions in <algorithm> and <utility> Headersand C++20 p1023 - constexpr comparison operators for std::array.The patch is large because of the testsuite additions. Basically, the algorithms and the array comparison operators are all marked constexpr for C++20. This has been built and tested on x86_64-linux.As discussed on IRC< the tests need to be run with -std=gnu++2a to ensure everything we test (which is not exhaustive, but is the best we can do) still works in C++2a mode. The indentation went bad here: template<typename _FIter1, typename _FIter2, typename _BinaryPredicate> - _FIter1 + _GLIBCXX20_CONSTEXPR + _FIter1 find_first_of(_FIter1, _FIter1, _FIter2, _FIter2, _BinaryPredicate);
Fixed.
I would have to look through old emails but I think there's a reason the function objects like _Iter_comp_to_val take their arguments by non-const reference. I'm very surprised that none of the algos that dispatch to __builtin_memove need changes, because those optimizations won't work in constant expressions. I would expect to have to use std::is_constant_evaluated to disable the optimizations when used in constant expressions.
As am I. As I mentioned on IRC I could roll a constexpr memmove.I was wondering if somehow I'm not checking what I think I'm checking (but I don't see how.)
I wonder if the builtins are handled differently somehow by the front end. I'm still not sure why __builtin_memcmp is OK for array == array but not array != array. In that case I just do element by element compare for constexpr now anyway.
Ed
2019-03-19 Edward Smith-Rowland <3dw...@verizon.net>
Implement C++20 p0202 - Add Constexpr Modifiers to Functions
in <algorithm> and <utility> Headers.
Implement C++20 p1023 - constexpr comparison operators for std::array.
* include/bits/algorithmfwd.h (all_of, any_of, binary_search, copy,
copy_backward, copy_if, copy_n, equal_range, fill, fill_n, find_end,
find_if_not, includes, is_heap, is_heap_until, is_partitioned,
is_permutation, is_sorted, is_sorted_until, lower_bound, none_of,
partition_copy, partition_point, remove, remove_if, remove_copy,
remove_copy_if, replace_copy, replace_copy_if, reverse_copy,
rotate_copy, unique, upper_bound, adjacent_find, count, count_if, equal,
find, find_first_of, find_if, for_each, generate, generate_n,
lexicographical_compare, merge, mismatch, replace, replace_if, search,
search_n, set_difference, set_intersection, set_symmetric_difference,
set_union, transform, unique_copy): Mark constexpr.
Make versions of operator() const.
* include/bits/cpp_type_traits.h (__miter_base): Make constexpr.
* include/bits/predefined_ops.h (_Iter_less_val, __iter_comp_val,
_Val_less_iter, __val_less_iter, __val_comp_iter, _Iter_equal_to_iter,
__iter_equal_to_iter, _Iter_equal_to_val, __iter_equal_to_val,
_Iter_comp_val, __iter_comp_val, _Val_comp_iter, __val_comp_iter,
_Iter_equals_val, __iter_equals_val, _Iter_equals_iter,
__iter_comp_iter, __pred_iter, __iter_comp_val, __negate): Constexpr
ctors. Add const operator().
* include/bits/stl_algo.h (__find_if, __find_if_not, __find_if_not_n,
__search, __search_n_aux, __search_n, __find_end, find_end, all_of
none_of, any_of, find_if_not, is_partitioned, partition_point,
__remove_copy_if, remove_copy, remove_copy_if, copy_if, __copy_n,
copy_n, partition_copy, __remove_if, remove, remove_if, __adjacent_find,
__unique, unique, __unique_copy, reverse_copy, rotate_copy,
__unguarded_linear_insert, __insertion_sort, __unguarded_insertion_sort,
__final_insertion_sort, lower_bound, __upper_bound, upper_bound,
__equal_range, equal_range, binary_search, __includes, includes,
__next_permutation, __prev_permutation, __replace_copy_if, replace_copy,
replace_copy_if, __count_if, is_sorted, __is_sorted_until,
is_sorted_until, __is_permutation, is_permutation, for_each, find,
find_if, find_first_of, adjacent_find, count, count_if, search,
search_n, transform, replace, replace_if, generate, generate_n,
unique_copy, __merge, merge, __set_union, set_union, __set_intersection,
set_intersection, __set_difference, set_difference,
__set_symmetric_difference, set_symmetric_difference): Constexpr.
* include/bits/stl_algobase.h (__niter_base, __niter_wrap, __copy_m,
__copy_move_a, copy, move, __copy_move_backward::__copy_move_b,
__copy_move_backward_a, __copy_move_backward_a2, copy_backward,
move_backward, fill, __fill_n_a, fill_n, __equal::equal, __equal_aux,
__newlast1, __cnd2, __newlast1, __cnd2, __lexicographical_compare_impl
__lexicographical_compare::__lc, __lexicographical_compare,
__lexicographical_compare_aux, __lower_bound, lower_bound, equal,
__equal4, lexicographical_compare, __mismatch, mismatch): Constexpr.
* include/bits/stl_heap.h (__is_heap_until, __is_heap, is_heap_until,
is_heap): Constexpr.
* include/bits/stl_iterator.h (__niter_base, __miter_base): Constexpr.
* include/std/array: Make comparison ops constexpr.
* include/std/utility: Make exchange constexpr.
* testsuite/23_containers/array/tuple_interface/get_neg.cc: Adjust.
* testsuite/23_containers/array/tuple_interface/
tuple_element_neg.cc: Adjust.
* testsuite/20_util/exchange/constexpr.cc: New.
* testsuite/23_containers/array/comparison_operators/constexpr.cc: New.
* testsuite/25_algorithms/headers/algorithm/synopsis.cc: Constexpr.
* testsuite/25_algorithms/adjacent_find/constexpr.cc: New.
* testsuite/25_algorithms/all_of/constexpr.cc: New.
* testsuite/25_algorithms/any_of/constexpr.cc: New.
* testsuite/25_algorithms/binary_search/constexpr.cc: New.
* testsuite/25_algorithms/copy/constexpr.cc: New.
* testsuite/25_algorithms/copy_backward/constexpr.cc: New.
* testsuite/25_algorithms/copy_if/constexpr.cc: New.
* testsuite/25_algorithms/copy_n/constexpr.cc: New.
* testsuite/25_algorithms/count/constexpr.cc: New.
* testsuite/25_algorithms/count_if/constexpr.cc: New.
* testsuite/25_algorithms/equal/constexpr.cc: New.
* testsuite/25_algorithms/equal_range/constexpr.cc: New.
* testsuite/25_algorithms/fill/constexpr.cc: New.
* testsuite/25_algorithms/fill_n/constexpr.cc: New.
* testsuite/25_algorithms/find/constexpr.cc: New.
* testsuite/25_algorithms/find_end/constexpr.cc: New.
* testsuite/25_algorithms/find_first_of/constexpr.cc: New.
* testsuite/25_algorithms/find_if/constexpr.cc: New.
* testsuite/25_algorithms/find_if_not/constexpr.cc: New.
* testsuite/25_algorithms/for_each/constexpr.cc: New.
* testsuite/25_algorithms/generate/constexpr.cc: New.
* testsuite/25_algorithms/generate_n/constexpr.cc: New.
* testsuite/25_algorithms/is_heap/constexpr.cc: New.
* testsuite/25_algorithms/is_heap_until/constexpr.cc: New.
* testsuite/25_algorithms/is_partitioned/constexpr.cc: New.
* testsuite/25_algorithms/is_permutation/constexpr.cc: New.
* testsuite/25_algorithms/is_sorted/constexpr.cc: New.
* testsuite/25_algorithms/is_sorted_until/constexpr.cc: New.
* testsuite/25_algorithms/lexicographical_compare/constexpr.cc: New.
* testsuite/25_algorithms/lower_bound/constexpr.cc: New.
* testsuite/25_algorithms/merge/constexpr.cc: New.
* testsuite/25_algorithms/mismatch/constexpr.cc: New.
* testsuite/25_algorithms/none_of/constexpr.cc: New.
* testsuite/25_algorithms/partition_copy/constexpr.cc: New.
* testsuite/25_algorithms/partition_point/constexpr.cc: New.
* testsuite/25_algorithms/remove/constexpr.cc: New.
* testsuite/25_algorithms/remove_copy/constexpr.cc: New.
* testsuite/25_algorithms/remove_copy_if/constexpr.cc: New.
* testsuite/25_algorithms/remove_if/constexpr.cc: New.
* testsuite/25_algorithms/replace_copy/constexpr.cc: New.
* testsuite/25_algorithms/replace_copy_if/constexpr.cc: New.
* testsuite/25_algorithms/replace_if/constexpr.cc: New.
* testsuite/25_algorithms/reverse_copy/constexpr.cc: New.
* testsuite/25_algorithms/rotate_copy/constexpr.cc: New.
* testsuite/25_algorithms/search/constexpr.cc: New.
* testsuite/25_algorithms/search_n/constexpr.cc: New.
* testsuite/25_algorithms/set_difference/constexpr.cc: New.
* testsuite/25_algorithms/set_intersection/constexpr.cc: New.
* testsuite/25_algorithms/set_symmetric_difference/constexpr.cc: New.
* testsuite/25_algorithms/set_union/constexpr.cc: New.
* testsuite/25_algorithms/transform/constexpr.cc: New.
* testsuite/25_algorithms/unique/constexpr.cc: New.
* testsuite/25_algorithms/unique_copy/constexpr.cc: New.
* testsuite/25_algorithms/upper_bound/constexpr.cc: New.
patch_constexpr_lib.bz2
Description: application/bzip
