reserved identifier violation

[elfring]

I would like to point out that identifiers like "__ARENA_H__" and "__TRAILDB_H__" do not fit to the expected naming convention of the C++ language standard.
Would you like to adjust your selection for unique names?

[whackashoe]

Well this is C not C++, but in 7.1.3 of the C standard:

All identifiers that begin with an underscore and either an uppercase letter or another underscore are always reserved for any use.

So yeah, would be best if someone changed this.

[tuulos]

Good point. We should change this.