Re: [PATCH] Extend std::copy/std::copy_n char* overload to deque iterator

[Jonathan Wakely via Gcc-patches]

On 07/05/20 09:12 +0200, François Dumont via Libstdc++ wrote:

    This patch purpose is to make sure that existing std::copy/std::copy_n overloads for char* will also be used for std::deque<char> iterators when dealing with istreambuf_iterator. It also make sure that it still works when _GLIBCXX_DEBUG is activated.

    * include/bits/stl_algo.h (__copy_n_a): Move to ...
    * include/bits/stl_algobase.h (__copy_n_a): ...here. Add __strict
    parameter.
    (__niter_base(const _Safe_iterator<_Ite, _Seq,
    random_access_iterator_tag>&)): New declaration.
    (__copy_move_a2(istreambuf_iterator<>, istreambuf_iterator<>,
    _Deque_iterator<>)): New declaration.
    (__copy_n_a(istreambuf_iterator<>, _Size, _Deque_iterator<>, bool)):
    New declaration.
    * include/bits/deque.tcc
    (__copy_move_a2(istreambuf_iterator<>, istreambuf_iterator<>,
    _Deque_iterator<>)): Add definition.
    (__copy_n_a(istreambuf_iterator<>, _Size, _Deque_iterator<>, bool)):
    Add definition.
    * include/bits/streambuf_iterator.h
    (__copy_n_a(istreambuf_iterator<>, _Size, _CharT*, bool)): Adapt
    definition.
    * include/debug/safe_iterator.tcc (__niter_base): Add definition.
    * testsuite/25_algorithms/copy/streambuf_iterators/char/4.cc (test03):
    New.
    * testsuite/25_algorithms/copy/streambuf_iterators/char/debug/
    deque_neg.cc: New.
    * testsuite/25_algorithms/copy_n/debug/istreambuf_ite_deque_neg.cc:
    New.
    * testsuite/25_algorithms/copy_n/istreambuf_iterator/2.cc: New.
    * testsuite/25_algorithms/copy_n/istreambuf_iterator/deque.cc: New.

Already tested for a while on Linux x64 normal and debug modes but I am currently rebuilding everything and will commit only once all succeeded again.

Ok ?

François

diff --git a/libstdc++-v3/include/bits/deque.tcc 
b/libstdc++-v3/include/bits/deque.tcc
index e773f32b256..45207066c48 100644
--- a/libstdc++-v3/include/bits/deque.tcc
+++ b/libstdc++-v3/include/bits/deque.tcc
@@ -1065,6 +1065,57 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
      return __result;
    }

+#if __cplusplus >= 201103L

Why is the optimization not done for C++03 mode?

It looks like the uses of 'auto' can be reaplced easily, and
__enable_if_t<> can be replaced with __gnu_cxx::__enable_if<>::__type.