Use STRICT_R_HEADERS in Rcpp.h

[jeroen]

This is only a simple suggestion. It defines STRICT_R_HEADERS inside Rcpp.h to prevent issues like #612 in the future.

I would be much in favor of setting STRICT_R_HEADERS unconditionally, but that might break an existing package or two (or perhaps not).

[eddelbuettel]

Please don't do pull requests before discussion.

I though of this as soon as you raised the issue. But we were just burned somewhere else by another package doing something 'too widely' in its header so I am against unconditional inclusion.

[jeroen]

Well the PR is not unconditionally. If it was not previously defined, it will undefine it at the end. So STRICT_R_HEADERS is only defined inside Rcpp.h.

[eddelbuettel]

Well but as the proponent of the proposal, it is would appear to be your responsibility to assess how widely it affects client packages. For that you would need to run reverse depends.

If it were unconditional, it wouldn't fail Travis either. So you have your counter proof right here, no? (Though it may pass once we clean up sample.h.)

Would you be terribly upset if I closed this here and we carry on over in #614?

[jeroen]

It fails because of #612 which is precisely the goal of the PR. Once the bug has been fixed it will no longer fail. But feel free to close I was just trying to discuss this suggestion here. You can move it to another issue.

[eddelbuettel]

I do hate red in Travis so submitting this now before we got to the fix needed to pass strikes me as ... suboptimal.