Any interest to `boost::find_gap` function?

```
std::vector nums = {6,7,8,10,11}; // lost 9
boost::find_gap(nums, 6); // will point to value 10 at index 3
```
This function is useful for validating sorted data that are expected to be consecutive integers, for example - packet ids that might be lost, unix timestamps in a video archive that might be sparsed, etc..

The issue names no files, tests, or entry points in the Boost.Algorithm module. Start by reviewing the issue and the module's existing algorithm conventions; done requires an agreed API and behavior for finding a gap in sorted consecutive integers, with tests covering the stated example and relevant edge cases.

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