Hi, thanks for your patch, and sorry it took me so long to respond.
On 08/18/2012 11:02 AM, Jiří Paleček wrote:
The idea of the fix is to postpone the decision whether or not to capture later to the template instantiation. This is because until then, we cannot know if the variable fulfills the conditions for a constant expression or not. So the patch assumes that if the constant value is a VAR_DECL (which is what I've found to happen in the debugger, although I'm not sure this is the only case) and we are in a template declaration, it just leaves the id expression there as is.
Thanks, I've now committed a simpler version of this that doesn't even bother calling integral_constant_value in templates.
Then the patch fiddles with the capture list in template instantiation code. Because new captures can be added while processing the template, we need to concatenate them with the original list from the template, plus there's a small hack to avoid producing the lambda-to-function-pointer conversion operator while we still don't have the final capture list.
I think a cleaner way to deal with the conversion issue would be to instantiate the capture list in instantiate_class_template_1 instead of here, so that we can do it in between the members and the conversion op.
I have produced two tests (in the patch) and ran the testsuite in the gcc subdirectory successfully. I've also tested the behavior on a testcase in the attached test.cpp file (it should print ok with all possible combinations of #defined macros).
Could you adjust the testcase so that it will work in the testsuite? Thanks, Jason
