Movement Algorithms

# Handling Overlapping Ranges

## How do you handle overlapping ranges when using std::ranges::move()?

When using std::ranges::move(), handling overlapping ranges can be tricky because it can lead to undefined behavior if not managedÂ correctly.

The key is to ensure that the destination range does not overlap with the source range in a way that would overwrite elements that are yet to beÂ moved.

### Using std::ranges::move_backward()

One effective way to handle overlapping ranges is to use std::ranges::move_backward() instead of std::ranges::move().

This algorithm moves elements from right to left, which helps avoid overwriting elements that haven't been movedÂ yet.

Here's anÂ example:

#include <algorithm>
#include <iostream>
#include <vector>

int main() {
std::vector<int> values{1, 2, 3, 4, 5};

// Move elements two positions to the right
std::ranges::move_backward(values.begin(),
values.begin() + 3,
values.end());

for (const auto& value : values) {
std::cout << value << ", ";
}
}
1, 2, 1, 2, 3,

In this example, move_backward() is used to shift elements to the right without causing overlapÂ issues.

### Guidelines

If moving left, use std::ranges::move():

std::ranges::move(
container.begin() + 2,
container.end(),
container.begin()
);

If moving right, use std::ranges::move_backward():

std::ranges::move_backward(
container.begin(),
container.end() - 2,
container.end()
);

### Conclusion

When dealing with overlapping ranges, std::ranges::move_backward() is often the safer choice to ensure elements are moved correctly without causing undefinedÂ behavior.

By moving elements from right to left, it prevents the overwriting of elements that are yet to beÂ moved.

This Question is from the Lesson:

### Movement Algorithms

An introduction to the seven movement algorithms in the C++ standard library: move(), move_backward(), rotate(), reverse(), shuffle(), shift_left(), and shift_right().

Answers to questions are automatically generated and may not have been reviewed.

This Question is from the Lesson:

### Movement Algorithms

An introduction to the seven movement algorithms in the C++ standard library: move(), move_backward(), rotate(), reverse(), shuffle(), shift_left(), and shift_right().

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