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Add alloc_construct_n overload for input iterators

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Glen Fernandes
2019-05-11 12:37:48 -04:00
parent b0df75ad1c
commit 6b65cde816
3 changed files with 51 additions and 0 deletions
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13
doc/alloc_construct.qbk
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@ -67,6 +67,9 @@ void alloc_construct_n(A& a, T* p, std::size_t n);
template<class A, class T> template<class A, class T>
void alloc_construct_n(A& a, T* p, std::size_t n, const T* l, std::size_t m); void alloc_construct_n(A& a, T* p, std::size_t n, const T* l, std::size_t m);
template<class A, class T, class I>
void alloc_construct_n(A& a, T* p, std::size_t n, I begin);
} /* boost */ } /* boost */
``` ```
@ -109,6 +112,16 @@ const T* l, std::size_t m);`]
`std::allocator_traits<A>::construct(a, &p[i], l[i % m])`.]] `std::allocator_traits<A>::construct(a, &p[i], l[i % m])`.]]
[[Remarks] [[Remarks]
[If an exception is thrown destroys each already constructed `j`-th element in [If an exception is thrown destroys each already constructed `j`-th element in
reverse order by calling `std::allocator_traits<A>::destroy(a, &p[j])`.]]]]]
[[`template<class A, class T, class I> void alloc_construct_n(A& a, T* p,
std::size_t n, I begin);`]
[[variablelist
[[Requires][`A` is an /Allocator/; `I` is an /InputIterator/]]
[[Effects]
[Constructs each `i`-th element in order by calling
`std::allocator_traits<A>::construct(a, &p[i], *begin++])`.]]
[[Remarks]
[If an exception is thrown destroys each already constructed `j`-th element in
reverse order by calling `std::allocator_traits<A>::destroy(a, &p[j])`.]]]]]] reverse order by calling `std::allocator_traits<A>::destroy(a, &p[j])`.]]]]]]
[endsect] [endsect]

22
include/boost/core/alloc_construct.hpp
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@ -130,6 +130,17 @@ alloc_construct_n(A& a, T* p, std::size_t n, const T* l, std::size_t m)
} }
hold.size() = 0; hold.size() = 0;
} }
template<class A, class T, class I>
inline void
alloc_construct_n(A& a, T* p, std::size_t n, I b)
{
detail::alloc_destroyer<A, T> hold(a, p);
for (std::size_t& i = hold.size(); i < n; void(++i), void(++b)) {
std::allocator_traits<A>::construct(a, p + i, *b);
}
hold.size() = 0;
}
#else #else
template<class A, class T> template<class A, class T>
inline void inline void
@ -202,6 +213,17 @@ alloc_construct_n(A& a, T* p, std::size_t n, const T* l, std::size_t m)
} }
hold.size() = 0; hold.size() = 0;
} }
template<class A, class T, class I>
inline void
alloc_construct_n(A& a, T* p, std::size_t n, I b)
{
detail::alloc_destroyer<A, T> hold(a, p);
for (std::size_t& i = hold.size(); i < n; void(++i), void(++b)) {
::new(static_cast<void*>(p + i)) T(*b);
}
hold.size() = 0;
}
#endif #endif
} /* boost */ } /* boost */

16
test/alloc_construct_test.cpp
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@ -105,6 +105,21 @@ void test_construct_n_list()
a.deallocate(p, 3); a.deallocate(p, 3);
} }
void test_construct_n_iterator()
{
boost::default_allocator<type> a;
type* p = a.allocate(3);
type l[] = { type(1), type(2), type(3) };
boost::alloc_construct_n(a, p, 3, &l[0]);
BOOST_TEST_EQ(type::count, 6);
BOOST_TEST_EQ(p[0].value(), 1);
BOOST_TEST_EQ(p[1].value(), 2);
BOOST_TEST_EQ(p[2].value(), 3);
boost::alloc_destroy_n(a, p, 3);
BOOST_TEST_EQ(type::count, 3);
a.deallocate(p, 3);
}
int main() int main()
{ {
test_construct(); test_construct();
@ -115,5 +130,6 @@ int main()
#endif #endif
test_construct_n(); test_construct_n();
test_construct_n_list(); test_construct_n_list();
test_construct_n_iterator();
return boost::report_errors(); return boost::report_errors();
} }