std::ranges...++,--,+=,-=(3)

✨ std::ranges::slide_view::iterator::operator++,--,+=,-= ✨

okay bestie, this is the C++ Standard Libary manpage for the slide_view iterator’s movement operators. It’s giving “iterator cardio” and honestly it ate. Let’s go 💅

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🌸 NAME 🌸

std::ranges::slide_view::iterator::operator++,--,+=,-= -
std::ranges::slide_view::iterator::operator++,--,+=,-=

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🦋 Synopsis 🦋

Every single one of these is constexpr and (since C++23). Here’s the synopsis, verbatim bestie:

constexpr /*iterator*/& operator++();                   (1) (since C++23)
constexpr /*iterator*/ operator++( int );               (2) (since C++23)
constexpr /*iterator*/& operator--()                    (3) (since C++23)
    requires ranges::bidirectional_range<Base>;
constexpr /*iterator*/ operator--( int )                (4) (since C++23)
    requires ranges::bidirectional_range<Base>;
constexpr /*iterator*/& operator+=( difference_type n ) (5) (since C++23)
    requires ranges::random_access_range<Base>;
constexpr /*iterator*/& operator-=( difference_type n ) (6) (since C++23)
    requires ranges::random_access_range<Base>;

Advances or decrements the iterator.

Let current_ and last_ele_ be the underlying iterators to the begin and end of the sliding window.

• (1) operator++() — equivalent to:

current_ = ranges::next(current_);
last_ele_ = ranges::next(last_ele_); // if last_ele_ is present
return *this;

Before the invocation, the current_ and last_ele_ (if present) must be incrementable.

• (2) operator++( int ) — equivalent to:

auto tmp = *this; ++*this; return tmp;

• (3) operator--() — equivalent to:

current_ = ranges::prev(current_);
last_ele_ = ranges::prev(last_ele_); // if last_ele_ is present
return *this;

Before the invocation, the current_ and last_ele_ (if present) must be decrementable.

• (4) operator--( int ) — equivalent to:

auto tmp = *this; --*this; return tmp;

• (5) operator+=( difference_type n ) — equivalent to:

current_ = current_ + n;
last_ele_ = last_ele_ + n; // if last_ele_ is present
return *this;

Before the invocation, the expressions current_ + n and last_ele_ + n (if last_ele_ is present) must have well-defined behavior.

• (6) operator-=( difference_type n ) — equivalent to:

current_ = current_ - n;
last_ele_ = last_ele_ - n; // if last_ele_ is present
return *this;

Before the invocation, the expressions current_ - n and last_ele_ - n (if last_ele_ is present) must have well-defined behavior.

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🎀 Parameters 🎀

• n — position relative to current location.

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💖 Return value 💖

• 1, 3, 5, 6) *this
• 2, 4) a copy of *this that was made before the change

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🧚 Example 🧚

This section is incomplete.

Reason: no example.

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👑 See also 👑

• operator+ performs iterator arithmetic
• operator- (function) (C++23)

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🌈 Category 🌈

• Todo no example

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Source/version + date check, bestie: this came from http://cppreference.com, dated 2024.06.10, and the page is std::ranges...++,--,+=,-=(3). Periodt 💅✨🫶