> On Feb. 25, 2019, 11:05 p.m., Benjamin Mahler wrote:
> > 3rdparty/stout/include/stout/os/posix/mktemp.hpp
> > Lines 39-57 (original), 39-57 (patched)
> > <https://reviews.apache.org/r/70053/diff/1/?file=2126763#file2126763line39>
> >
> >     From what I understand, C++11 already guarantees for us that 
> > `_path[_path.size()] == '\0'` and so we shouldn't need this +1 and '\0' 
> > logic?
> >     
> >     ```
> >       std::string _path(path);
> >     
> >       int_fd fd = ::mkstemp(&_path[0]);
> >       
> >       ...
> >       
> >       return _path;
> >     ```

I read that, too.

Note that here we do not evaluate `_path[_path.size()]` directly, but instead 
pass `&_path[0]` to a function expecting a null-terminated string. AFAICT no 
C++ standard makes promises about `string` actually null-terminating strings 
internally (e.g., `_path.data()` which would be equivalent to `&_path[0]` isn't 
per se uaranteed to point to a null-terminated string in even the most recent 
standard), and the only reference to automatically null-terminating strings I 
could find were related to explicitly accessing the `size()`'th element, and 
`string::c_str`, neither of which return the internal buffer we are using here.

I believe what I do here is needed.


- Benjamin


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On Feb. 25, 2019, 10:20 p.m., Benjamin Bannier wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/70053/
> -----------------------------------------------------------
> 
> (Updated Feb. 25, 2019, 10:20 p.m.)
> 
> 
> Review request for mesos and Benjamin Mahler.
> 
> 
> Repository: mesos
> 
> 
> Description
> -------
> 
> This is a non-functional change to avoid manual memory management. By
> using a `std::string` instead of an explicitly heap-allocated buffer the
> used pattern might even avoid hitting the heap altogether due to the SSO
> but this function might be runtime bounded by I/O anyway.
> 
> 
> Diffs
> -----
> 
>   3rdparty/stout/include/stout/os/posix/mktemp.hpp 
> 8dab2599f13c3e1dab109423c8a938ec16540aaf 
> 
> 
> Diff: https://reviews.apache.org/r/70053/diff/1/
> 
> 
> Testing
> -------
> 
> `make check`
> 
> 
> Thanks,
> 
> Benjamin Bannier
> 
>

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