<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/189646>189646</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang-tidy] Add `modernize-use-std-clamp` check
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang-tidy,
            check-request
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          unterumarmung
      </td>
    </tr>
</table>

<pre>
    A modernization check for canonical clamp-shaped code would still be useful in real C++17 codebases. The obvious target is nested `min`/`max` expressions such as `std::min(std::max(x, lo), hi)` and equivalent ternary ladders that are really just spelling `std::clamp(x, lo, hi)` by hand.

This pattern is easy to recognize once you know it, but in production code it is still noisier than the intent deserves. Hand-written clamp logic makes reviewers re-parse boundary handling, increases the chance of subtle inconsistencies between sites, and can hide bugs when one branch is edited incorrectly or the order of comparisons drifts. `std::clamp` expresses the operation directly and makes the code read as a bounded value rather than as control flow.

Typical “happy path” examples would be things like:

```cpp
auto y = std::min(std::max(x, lo), hi);
```

```cpp
value = std::max(lo, std::min(value, hi));
```

```cpp
return x < lo ? lo : (hi < x ? hi : x);
```

These are common, mechanically recognizable spellings of a clamp, and replacing them with `std::clamp` would usually improve readability immediately.
</pre>
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