# Bug with Cpp Standard 20

**URL:** https://discourse.vtk.org/t/bug-with-cpp-standard-20/14679
**Category:** Support
**Created:** [October 8, 2024, 12:14pm UTC](https://discourse.vtk.org/t/bug-with-cpp-standard-20/14679 "2024-10-08T12:14:10Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Msd](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/m/e79b87/32.png) [@Msd](https://discourse.vtk.org/u/Msd)
#### Post date: [October 8, 2024, 12:14pm UTC](https://discourse.vtk.org/t/bug-with-cpp-standard-20/14679/1 "2024-10-08T12:14:10Z")

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I am trying to build VTK with CPP standard 20 and getting the following errors:  
vtkSMPToolsImpl.cxx.obj : error LNK2005: “public: \_\_cdecl vtk::detail::smp::vtkSMPToolsImpl\<2\>::vtkSMPToolsImpl\<2\>(void)” (??0?$vtkSMPToolsImpl@$01@smp@detail@vtk@@QEAA@XZ) already defined in vtkSMPToolsAPI.obj

and  
vtkCommonCore.dll : fatal error LNK1169: one or more multiply defined symbols found [C:\Users\build\Common\Core\CommonCore.vcxproj]

Any idea how to solve these?

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### Author: ![dgobbi](https://discourse.vtk.org/user_avatar/discourse.vtk.org/dgobbi/32/18_2.png) [@dgobbi](https://discourse.vtk.org/u/dgobbi)
#### Post date: [October 8, 2024, 12:41pm UTC](https://discourse.vtk.org/t/bug-with-cpp-standard-20/14679/2 "2024-10-08T12:41:54Z")

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This was previously reported in [issue #19482](https://gitlab.kitware.com/vtk/vtk/-/issues/19482).  
It is fixed in the VTK master branch.