What is structured binding (C++17)?

Question

Accepted Answer

**Structured binding** — decompose aggregates into named variables.

```cpp
// With pair/tuple
auto [x, y] = std::make_pair(1, 2.0);

// With arrays
int arr[] = {10, 20, 30};
auto [a, b, c] = arr;

// With structs
struct Point { int x; int y; };
Point p{1, 2};
auto [px, py] = p;
```

**With maps:**
```cpp
std::map<std::string, int> m = {{"a", 1}};
for (const auto& [key, value] : m) {
    std::cout << key << ": " << value;
}
```

**Requirements:**
- Aggregate type or tuple-like
- Number of bindings matches elements
- All elements same access (public)

C++: What is structured binding (C++17)?