David Abrahams wrote:
Johan Paulsson <boost.org@kuodo.com> writes:
In this case, with the compilers I used, I do not see a big difference in quality of the error message.
Of course not, especially because in this case you seem to have left out all but the very useless ASSERT(false) case.
I made a different, in my opinion much better, test for compile time assertions in recursive templates. I put together a small web-page with source code and output from some compilers. Please have a look at <http://www.kuodo.com/code/assert/recurse/readme.html> Or download it (9kb) <http://www.kuodo.com/code/assert/recurse/recurse.zip> The test can be made to instantiate templates to a certain depth, and compile time assertions can be set to fail when a certain depth is instantiated, in class and/or function scope. The compiler back-trace shows the instatiation-depth (a int template argument), at least on the compilers I have used. In this case, I do see a difference with the Intel compiler. My implementation does not point to the line of the compile-time assert typedef. That is not very nice. The output says: ../recurse.hpp(27): error: class "tests::too_deep_in_function<5>" has no member "assert" If it said 80 instead of 27 it would point to the compile-time assert typedef. David, I think this is what you said in a previous message?
Also, the first test, which simply asserts a bool constant, is not very interesting from an error-message-quality point of view. You can't expect much useful information from such an assertion; it's similar to
assert(false);
at runtime.
I agree, I should have left it out of the compiler output.
So why did you throw out the only assertion that can possibly show useful results?
I think the output from the class-scope assertion that is included in the compiler output is useful, thogether with the source code for the test. I wanted to show, as briefly as possible, the basic usage of my implementation compared to something the readers of this mailing list would recognize. I think it does. It was not my intention to prove one implementation better than the other, or provide a very useful test, and I think I never implied that. Anyway, I am sorry you found it useless. /Johan Paulsson