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eclipse-cyclonedds / cyclonedds

Eclipse Cyclone DDS project
https://projects.eclipse.org/projects/iot.cyclonedds
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Do not #define restrict #2140

Open a-zw opened 3 days ago

a-zw commented 3 days ago

https://github.com/eclipse-cyclonedds/cyclonedds/blob/d8cef891b9a27cc7bc52477e1c7b2c3f8edf81ba/src/core/ddsc/include/dds/dds.h#L29

Since restrict is a valid C++ identifier, a macro should not make it disappear. It can lead to unnecessary errors in user code.

Example:

#include <dds/dds.h>
int restrict = 42;

Workaround is simple: Just rename the variable.

a-zw commented 3 days ago

There are other instance of suppressing restrict and __restrict but I don't know why, so naively removing it is probably not the solution?

eboasson commented 3 days ago

@a-zw I couldn't agree more, that #define restrict should not be there. It is kinda of safe to just remove all occurrences of restrict/__restrict from the sources, and at least for the API that would probably be a good plan. Then Cyclone can internally still do whatever.

Consistently using __restrict and defining that away could also be an option. Or just defining dds_restrict as restrict / nothing, depending on whether it is C or C++, and using that throughout.

I need to have a better look before making up my mind ...