# Custom Build Type
**URL:** https://discourse.cmake.org/t/custom-build-type/201
**Category:** Usage
**Created:** [November 13, 2019, 11:55pm UTC](https://discourse.cmake.org/t/custom-build-type/201 "2019-11-13T23:55:22Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@David\_Dixon](https://discourse.cmake.org/u/David_Dixon)
#### Post date: [November 13, 2019, 11:55pm UTC](https://discourse.cmake.org/t/custom-build-type/201/1 "2019-11-13T23:55:22Z")
Is there a idiomatic way to provide a custom build type? For example, if I want to have Release flags plus march=native and mtune=native how should I go about doing this? Certainly, I could add them to CMAKE\_CXX\_FLAGS when I invoke cmake but the devs on my team would like to have them baked in to a BUILD\_TYPE e.g. `-D CMAKE_BUILD_TYPE=Optimized` or something like that…
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### Author:  [@craig.scott](https://discourse.cmake.org/u/craig.scott)
#### Post date: [November 14, 2019, 1:40am UTC](https://discourse.cmake.org/t/custom-build-type/201/2 "2019-11-14T01:40:13Z")
One of the free sample chapters of my book shows how to do this. You can find it here:
> **[Professional CMake: A Practical Guide](https://crascit.com/professional-cmake/)**
>
> The handbook for every CMake user, providing structured learning, the latest best practices and real-world advice.
The free sample includes the whole _Build Types_ chapter, which includes a section on custom build types. That section includes an example which does exactly what you’re asking about.
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### Author:  [@David\_Dixon](https://discourse.cmake.org/u/David_Dixon)
#### Post date: [November 14, 2019, 3:13pm UTC](https://discourse.cmake.org/t/custom-build-type/201/3 "2019-11-14T15:13:30Z")
Thanks - buying it now!