README-qbytearray-conversion-to-c-style.md

qbytearray-conversion-to-c-style

Warns about usage of QByteArray to const char * implicit conversion operator. This sort of conversion is deemed dangerous given how const char * is a very common type. This can be fixed by making the conversion explicit, e.g. by using QByteArray::constData().

Note that this conversion operator can be disabled by defining the QBYTEARRAY_NO_CAST_TO_ASCII macro.

Caveats

For QByteArrayLiteral this check only works for Qt6 where QByteArrayLiteral is a macro, but not with Qt5 where QByteArrayLiteral is a lambda.

Example

void func(const char *);
QByteArray ba = "some text";
func(ba); // Bad, implicit conversion to const char *
func(ba.constData()); // Good, explicit conversion

func(QByteArrayLiteral("some literal")); // Bad, implicit conversion plus QByteArray allocation
func("some literal")); // Good, use the string literal directly

Fixits

This check supports a fixit to rewrite your code. See the README.md on how to enable it.