[clang-tools-extra] [clang-tidy] Add new check `modernize-use-structured-binding` (PR #158462)

[Baranov Victor via cfe-commits]

================
@@ -0,0 +1,58 @@
+.. title:: clang-tidy - modernize-use-structured-binding
+
+modernize-use-structured-binding
+================================
+
+Suggests using C++17 structured bindings to decompose pairs.
+
+This check finds three code patterns and recommends using structured bindings for clearer, more idiomatic C++17 code.
+
+1. Decompose a pair variable by assigning its members to separate variables right after its definition:
+
+.. code-block:: c++
+
+  auto p = getPair<int, int>();
+  int x = p.first;
+  int y = p.second;
+
+  into:
+
+  auto [x, y] = getPair<int, int>();
+
+2. Use `std::tie` to decompose a pair into two predefined variables:
+
+.. code-block:: c++
+
+  int a;
+  int b;
+  std::tie(a, b) = getPair<int, int>();
+
+  into:
+
+  auto [a, b] = getPair<int, int>();
+
+3. Manually decompose a pair by assigning to its members to local variables in a range-based for loop:
+
+.. code-block:: c++
+
+  for (autop : vecOfPairs) {
+    int x = p.first;
+    int y = p.second;
+    // ...
+  }
+
+  into:
+
+  for (auto [x, y] : vecOfPairs) {
+    // use x and y
+  }
+
+The check also supports custom pair-like types via the `PairTypes` option.
+
----------------
vbvictor wrote:

You should add "Limitations" section and place text from PR description there.

https://github.com/llvm/llvm-project/pull/158462