# One -Wunused-template warning left, anyone know how to fix it?

**URL:** <https://discourse.itk.org/t/one-wunused-template-warning-left-anyone-know-how-to-fix-it/871>\
**Category:** Engineering\
**Created:** [April 26, 2018, 2:26pm UTC](https://discourse.itk.org/t/one-wunused-template-warning-left-anyone-know-how-to-fix-it/871 "2018-04-26T14:26:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![seanm](https://discourse.itk.org/letter_avatar_proxy/v4/letter/s/a88e4f/32.png) [@seanm](https://discourse.itk.org/u/seanm)\
**Post date:** [April 26, 2018, 2:26pm UTC](https://discourse.itk.org/t/one-wunused-template-warning-left-anyone-know-how-to-fix-it/871/1 "2018-04-26T14:26:17Z")

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Hi all,

My bots have just one -Wunused-template warning left:

ITK/Modules/Core/Common/test/itkAggregateTypesTest.cxx:116:15: warning: unused function template ‘operator\<\<’ [-Wunused-template]  
std::ostream &operator\<\<(std::ostream &os,  
^

But my C+±fu to too weak… anyone know how to fix this?

Thanks,

Sean

---

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**Author:** ![matt.mccormick](https://discourse.itk.org/user_avatar/discourse.itk.org/matt.mccormick/32/7_2.png) [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)\
**Post date:** [April 26, 2018, 2:31pm UTC](https://discourse.itk.org/t/one-wunused-template-warning-left-anyone-know-how-to-fix-it/871/2 "2018-04-26T14:31:15Z")

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> [@seanm](#):
>
> My bots have just one -Wunused-template warning left:

Woohoo!

```auto
ITK/Modules/Core/Common/test/itkAggregateTypesTest.cxx:116:15: warning: unused function template ‘operator<<’ [-Wunused-template]
std::ostream &operator<<(std::ostream &os,
^

```

@hjmjohnson addressed this yesterday:

[http://review.source.kitware.com/#/c/23353/](http://review.source.kitware.com/#/c/23353/)