Differences between Qt cast and normal cast (and some questions about it)

Mihan

Hi
I want to know the differences between the cast like static_cast and (type)param

e.g.
some protocols' API will need `uint8_t*` param:
`bool writedata(uint8_t* data);`
but the data type from qt `QByteArray` is `char*`

some blogs say that it's unsafe to use reinterpret_cast. Could you tell me how to use these casts?I can't find the information about this in wiki

Regards
Mihan

aha_1980

Hi @Mihan,

the absolutely clean way is indeed to have a uint8_t buffer[] and to memcpy the QByteArray contents to it.

But if your API takes a const uint8_t *data pointer, I'd indeed go with reinterpret_cast:

QByteArray ba = "...";
const uint8_t *data = reinterpret_cast<const uint8_t *>(ba.constData());

Note that functions non-const parameters (uint8_t *data) might modify the data, which can lead to unexpected side effects of any kind when they operate on the byte array data.

Regards

SGaist

Hi,

Out of curiosity, what Qt cast do you have in mind ? Is see only C/C++ cast in your post.