a25321ca06
This rewrites our range adaptor implementation for more comprehensible error messages, improved SFINAE behavior and conformance to P2281. The diagnostic improvements mostly come from using appropriately named functors instead of lambdas in the generic implementation of partial application and composition of range adaptors, and in the definition of each of the standard range adaptors. This makes their pretty printed types much shorter and more self-descriptive. The improved SFINAE behavior comes from constraining the range adaptors' member functions appropriately. This improvement fixes PR99433, and is also necessary in order to implement the wording changes of P2281. Finally, P2281 clarified that partial application and composition of range adaptors behaves like a perfect forwarding call wrapper. This patch implements this, except that we don't bother adding overloads for forwarding captured state entities as non-const lvalues, since it seems sufficient to handle the const lvalue and non-const rvalue cases for now, given the current set of standard range adaptors. But such overloads can be easily added if they turn out to be needed. libstdc++-v3/ChangeLog: PR libstdc++/99433 * include/std/ranges (__adaptor::__maybe_refwrap): Remove. (__adaptor::__adaptor_invocable): New concept. (__adaptor::__adaptor_partial_app_viable): New concept. (__adaptor::_RangeAdaptorClosure): Rewrite, turning it into a non-template base class. (__adaptor::_RangeAdaptor): Rewrite, turning it into a CRTP base class template. (__adaptor::_Partial): New class template that represents partial application of a range adaptor non-closure. (__adaptor::__pipe_invocable): New concept. (__adaptor::_Pipe): New class template. (__detail::__can_ref_view): New concept. (__detail::__can_subrange): New concept. (all): Replace the lambda here with ... (_All): ... this functor. Add appropriate constraints. (__detail::__can_filter_view): New concept. (filter, _Filter): As in all/_All. (__detail::__can_transform): New concept. (transform, _Transform): As in all/_All. (__detail::__can_take_view): New concept. (take, _Take): As in all/_All. (__detail::__can_take_while_view): New concept. (take_while, _TakeWhile): As in all/_All. (__detail::__can_drop_view): New concept. (drop, _Drop): As in all/_All. (__detail::__can_drop_while_view): New concept. (drop_while, _DropWhile): As in all/_All. (__detail::__can_join_view): New concept. (join, _Join): As in all/_All. (__detail::__can_split_view): New concept. (split, _Split): As in all/_All. Rename template parameter _Fp to _Pattern. (__detail::__already_common): New concept. (__detail::__can_common_view): New concept. (common, _Common): As in all/_All. (__detail::__can_reverse_view): New concept. (reverse, _Reverse): As in all/_All. (__detail::__can_elements_view): New concept. (elements, _Elements): As in all/_All. (keys, values): Adjust. * testsuite/std/ranges/adaptors/99433.cc: New test. * testsuite/std/ranges/adaptors/all.cc: No longer expect that adding empty range adaptor closure objects to a pipeline doesn't increase the size of the pipeline. (test05): New test. * testsuite/std/ranges/adaptors/common.cc (test03): New test. * testsuite/std/ranges/adaptors/drop.cc (test09): New test. * testsuite/std/ranges/adaptors/drop_while.cc (test04): New test. * testsuite/std/ranges/adaptors/elements.cc (test04): New test. * testsuite/std/ranges/adaptors/filter.cc (test06): New test. * testsuite/std/ranges/adaptors/join.cc (test09): New test. * testsuite/std/ranges/adaptors/p2281.cc: New test. * testsuite/std/ranges/adaptors/reverse.cc (test07): New test. * testsuite/std/ranges/adaptors/split.cc (test01, test04): Adjust. (test09): New test. * testsuite/std/ranges/adaptors/split_neg.cc (test01): Adjust expected error message. (test02): Likewise. Extend test. * testsuite/std/ranges/adaptors/take.cc (test06): New test. * testsuite/std/ranges/adaptors/take_while.cc (test05): New test. * testsuite/std/ranges/adaptors/transform.cc (test07, test08): New test. |
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libsupc++ | ||
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config.h.in | ||
configure | ||
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README |
file: libstdc++-v3/README New users may wish to point their web browsers to the file index.html in the 'doc/html' subdirectory. It contains brief building instructions and notes on how to configure the library in interesting ways.