std::forward_list::before_begin, cbefore_begin - cppreference.com

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# std::forward_list::before_begin, cbefore_begin

From cppreference.com
< cpp‎ | container‎ | forward list

iterator before_begin(); |  | (since C++11)
const_iterator before_begin() const; |  | (since C++11)
const_iterator cbefore_begin() const; |  | (since C++11)

Returns an iterator to the element before the first element of the container. This element acts as a placeholder, attempting to access it results in undefined behavior. The only usage cases are in functions insert_after(), emplace_after(), erase_after(), splice_after() and the increment operator: incrementing the before-begin iterator gives exactly the same iterator as obtained from begin()/cbegin().

### [edit] Parameters

(none)

### [edit] Return value

Iterator to the element before the first element.

### [edit] Exceptions

`noexcept` specification:
noexcept

### [edit] Complexity

Constant.

### [edit] See also

begin cbegin | returns an iterator to the beginning (public member function) [edit]
end cend | returns an iterator to the end (public member function) [edit]

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Category:

- unconditionally noexcept