QStaticByteArrayMatcher Class▲
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Header: QStaticByteArrayMatcher
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Since: Qt 5.9
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qmake: QT += core
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Group: QStaticByteArrayMatcher is part of tools, string-processing
Detailed Description▲
This class is useful when you have a sequence of bytes that you want to repeatedly match against some byte arrays (perhaps in a loop), or when you want to search for the same sequence of bytes multiple times in the same byte array. Using a matcher object and indexIn() is faster than matching a plain QByteArray with QByteArray::indexOf(), in particular if repeated matching takes place.
Unlike QByteArrayMatcher, this class calculates the internal representation at compile-time, if your compiler supports C++14-level constexpr (C++11 is not sufficient), so it can even benefit if you are doing one-off byte array matches.
Create the QStaticByteArrayMatcher by calling qMakeStaticByteArrayMatcher(), passing it the C string literal you want to search for. Store the return value of that function in a static const auto variable, so you don't need to pass the N template parameter explicitly:
static const auto matcher = qMakeStaticByteArrayMatcher("needle");Then call indexIn() on the QByteArray in which you want to search, just like with QByteArrayMatcher.
Since this class is designed to do all the up-front calculations at compile-time, it does not offer a setPattern() method.
Qt detects the necessary C++14 compiler support by way of the feature test recommendations from C++ Committee's Standing Document 6.
See Also▲
See also QByteArrayMatcher, QStringMatcher