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.: clang has similar issues. Links: boost::di -> https://github.com/boost-experimental/di ECST -> https://github.com/SuperV1234/ecst
Most likely a dup of bug 17693.
(In reply to Andrew Pinski from comment #1) > Most likely a dup of bug 17693. I'll just put it under "See Also" until there's more certainty that this is a dup of it