-
Notifications
You must be signed in to change notification settings - Fork 15.2k
Description
Bugzilla Link | 27793 |
Version | trunk |
OS | Windows NT |
Extended Description
Long typenames, usually generated by heavy template metaprogramming code, result in errors that are extremely hard to read and parse. Furthermore, they slow down compilation time significantly.
Here's a benchmark and example from the boost::di project:
http://melpon.org/wandbox/permlink/7Fh0u2oaQbDmkNV0
The benchmark shows:
- How unnecessarily long and hard-to-understand errors are.
- How typename erasure techniques can improve compilation times (define TYPENAME_ERASURE to see compilation time improvements).
I've encountered this same issue in one of my projects (ECST) - errors were impossible to understand before GCC 6 was released. GCC 6's produced errors pinpoint the issue more accurately, but still produce an enormous amount of unnecessary output.
I think this is primarily a defect in error reporting. A flag to control long typename output would be desired and possibly necessary for projects that require the generation of long typenames.
I also think that having compilation times speed up when erasing typenames signals some sort of potential compilation optimization for long typenames.
P.S.: gcc has similar issues.
Links:
boost::di -> https://github.com/boost-experimental/di
ECST -> https://github.com/SuperV1234/ecst