On Tuesday, 22 January 2019 11:02:22 PST Matthew Woehlke wrote: > On 18/01/2019 11.09, Thiago Macieira wrote: > > As for strings, the QString constructor takes UTF-8 input, but however > > fast > > the decoder is, it's still slightly slower than the Latin1 decoder. So if > > your string is purely US-ASCII, using QLatin1String is recommended. > > ...but I assume QStringLiteral remains even faster? (I would think so; > not only is *no* decoding needed, which you could also get just by using > wide string literals, but also no *allocation*...)
Yes. In terms of CPU cycles, for a given string length of US-ASCII content: QUtf8::convertToUnicode > qt_from_latin1 > memcpy > ∅ (fromUtf8, fromLatin1, fromUtf16, QStringLiteral) The empty set symbol indicates that QStringLiteral is requires no operation on the content (O(1) on length). The others are O(n). -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center _______________________________________________ Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
