Fix conflict when importing C math library math.h

[germanmarques]

At the moment the C header math library is imported using quotes. However, if the project already has a math.h file is imported before the math.h C library file, having a conflict. Is it possible to import it using <>?

Thank you!

[XaviTorello]

Hi @eteq @mhvk any news about this PR?

Many thanks dudes!

[mhvk]

Sorry for the delay! This seems uncontroversial except that probably we should try to get it upstream to SOFA, to minimize the difference. Ping @PTW19 to see how we would go about that. In the meantime, I let CI run, which indeed shows that the tests do not care about this.

[germanmarques]

@mhvk How can we help to try to get it to SOFA? It seems like using <math.h> is the correct way to do it. cc/ @PTW19

[PTW19]

Can it really be that projects have their own header files with the same names as ones that have been in the C RTL for the past half century?

Having said that, I was startled to find that sofa.h really does include math.h using double quotes just as germanmarques reported. This is surely the wrong thing to do, as math.h is never going to be in the same directory as the program source, so using double quotes adds nothing to what the angle bracket form does. Should I ask the SOFA Board to revisit this issue?

[cxwx]

Indeed, there are cases where libraries define their own custom header files, which can potentially cause conflicts. which is quite an annoying legacy issue. However, the best approach is to avoid using filenames like "math.h" or "time.h" in your own project.
Indeed, some people may attempt to replace the location of "math.h" and libraries to substitute the system libraries. In such cases, using angle brackets < > for include statements might be inconvenient.

[germanmarques]

Can it really be that projects have their own header files with the same names as ones that have been in the C RTL for the past half century?

Having said that, I was startled to find that sofa.h really does include math.h using double quotes just as germanmarques reported. This is surely the wrong thing to do, as math.h is never going to be in the same directory as the program source, so using double quotes adds nothing to what the angle bracket form does. Should I ask the SOFA Board to revisit this issue?

Yes, it happens :)
https://github.com/CesiumGS/cesium-native/blob/main/CesiumUtility/include/CesiumUtility/Math.h

[mhvk]

@PTW19 - it would seem to be that one might as well use the <> to indicate one expects to use the standard library. So, if you can ask the SOFA board, that would be great!