# std::ranges::subrange<I,S,K>::prev

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< cpp‎ | ranges‎ | subrange

[[nodiscard]] constexpr subrange prev( std::iter_difference_t<I> n = 1 ) const requires std::bidirectional_iterator<I>; |  | (since C++20)

Obtains a `subrange` whose iterator is decremented by `n` times or incremented by `min(-n, size())` times respect to that of *this, when `n >= 0` or `n < 0` respectively.

Equivalent to auto tmp = *this; tmp.advance(-n); return tmp;. The behavior is undefined if the iterator is decremented after being a non-decrementable value.

### Parameters

n | - | number of minimal decrements of the iterator

### Return value

A `subrange` whose iterator is decremented by `n` times or incremented by `min(-n, size())` times respect to that of *this, when `n >= 0` or `n < 0` respectively.

### Complexity

Generally `n` decrements or `min(-n, size())` increments on the iterator, when `n >= 0` or `n < 0` respectively.

Constant if `I` models `random_access_iterator`, and either `n >= 0` or std::sized_sentinel_for<S, I> is modeled.

### Example

| This section is incomplete Reason: no example

### See also

next (C++20) | obtains a copy of the `subrange` with its iterator advanced by a given distance (public member function)
advance (C++20) | advances the iterator by given distance (public member function)
prev (C++11) | decrement an iterator (function template)
ranges::prev (C++20) | decrement an iterator by a given distance or to a bound (niebloid)

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