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Showing content from https://en.cppreference.com/w/cpp/language/../memory/uninitialized_copy.html below:

std::uninitialized_copy - cppreference.com

template< class InputIt, class NoThrowForwardIt >

NoThrowForwardIt uninitialized_copy( InputIt first, InputIt last,

                                     NoThrowForwardIt d_first );
(1) (constexpr since C++26) template< class ExecutionPolicy, class ForwardIt,

          class NoThrowForwardIt >
NoThrowForwardIt uninitialized_copy( ExecutionPolicy&& policy,
                                     ForwardIt first, ForwardIt last,

                                     NoThrowForwardIt d_first );
(2) (since C++17) 1)

Copies elements from the range

[firstlast)

to an uninitialized memory area beginning at

d_first

as if by

for (; first != last; ++d_first, (void) ++first)
    ::new (voidify(*d_first))
        typename std::iterator_traits<NoThrowForwardIt>::value_type(*first);

If an exception is thrown during the initialization, the objects already constructed are destroyed in an unspecified order.

2) Same as (1), but executed according to policy.

This overload participates in overload resolution only if all following conditions are satisfied:

If d_first + [​0​std::distance(first, last)) overlaps with [firstlast), the behavior is undefined.

(since C++20) [edit] Parameters first, last - the pair of iterators defining the range of elements to copy d_first - the beginning of the destination range policy - the execution policy to use Type requirements -InputIt must meet the requirements of LegacyInputIterator. -ForwardIt must meet the requirements of LegacyForwardIterator. -NoThrowForwardIt must meet the requirements of LegacyForwardIterator. -No increment, assignment, comparison, or indirection through valid instances of NoThrowForwardIt may throw exceptions. Applying &* to a NoThrowForwardIt value must yield a pointer to its value type.(until C++11) [edit] Return value

Iterator to the element past the last element copied.

[edit] Complexity

Linear in the distance between first and last.

[edit] Exceptions

The overload with a template parameter named ExecutionPolicy reports errors as follows:

[edit] Notes [edit] Possible implementation
template<class InputIt, class NoThrowForwardIt>
constexpr NoThrowForwardIt uninitialized_copy(InputIt first, InputIt last,
                                              NoThrowForwardIt d_first)
{
    using T = typename std::iterator_traits<NoThrowForwardIt>::value_type;
    NoThrowForwardIt current = d_first;
    try
    {
        for (; first != last; ++first, (void) ++current)
            ::new (static_cast<void*>(std::addressof(*current))) T(*first);
        return current;
    }
    catch (...)
    {
        for (; d_first != current; ++d_first)
            d_first->~T();
        throw;
    }
}
[edit] Example [edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior LWG 866 C++98 given T as the value type of NoThrowForwardIt, if
T::operator new exists, the program might be ill-formed uses global replacement-
new instead LWG 2133 C++98 the effect description used a for loop with the iteration
expression ++d_first, ++first, which results
in an argument-dependent lookup of operator, discards the value
of one operand
to disable that ADL LWG 2433 C++11 this algorithm might be hijacked by overloaded operator& uses std::addressof LWG 3870 C++20 this algorithm might create objects on a const storage kept disallowed [edit] See also

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