Abel, After looking at Metaparse, I inquired on the c++std-ext list as to whether user-defined operators can create char packs from integer or floating point literals, but not from string literals, as this would have made the MPLLIBS_STRING macro unnecessary. As it turns out, there has been such a proposal, N3599: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3599.html later referenced by two competing proposals for compile-time string literals, N4121 and N4236: https://isocpp.org/files/papers/n4121.pdf http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4236.html N3599 has been however rejected, as the committee apparently feels that representing compile-time strings as char packs is inefficient and impractical, and prefers constexpr char arrays. I cited Metaparse as an argument that char packs are quite obviously practical if they work in practice, and was asked whether measurement data has been presented as part of the formal review, perhaps compared to alternatives. I'm not aware of any alternatives to Metaparse though, so this question may be hard to answer. :-) Either way, the only performance data I see is http://abel.web.elte.hu/mpllibs/metaparse/performance.html which seems rather slim. Is there any other? (On an unrelated note, the cpp-next.com link is dead, but archive.org still has it at http://web.archive.org/web/20140217173026/http://cpp-next.com/archive/2012/1...).