Is it impossible to write 4 bytes for a float and 8 for double at QdataStream ?

[tonnot]

I need (I must) to write a lot of floats to a qdatastream and it is neccesary I use only 4 bytes.
setFloatingPointPrecision or writes 4 or 8 both for floats and doubles.
I thought that it was applicable to qreal, but I surprise it works on float a double type..

Is there any solution ? Thanks

[MarekR22]

Read documentation!!!
Documentation of QDataStream::setFloatingPointPrecision clearly says that this behavior writing doubles and floats depends on data steam version.
So you have to call setVersion with value QDataStream::Qt_4_5 or lower.
Note also that they recommend that you should read "Versioning" section.

[ChrisW67]

Is the float binary size an issue because you using a QDataStream to write a binary file to be interpreted by a non-Qt program? If so you probably should just avoid QDataStream and write directly to a QIODevice. If there is anything other than individual intrinsic data types in the QDataStream then chances are the other end will have fun interpreting it.

[MarekR22]

based on his other topics I would say it is good he is using this class. He plans to run his program with diffrent platforms so he have to handle endians and so on.

[tonnot]

The solution consist int having two functions, one for float and the other a typical template. For float QDataStream::setFloatingPointPrecision to 4 and 8 for the other. I dont know that QDataStream::setFloatingPointPrecision could be set at any moment, by mistake, I thought that the setting was make for all the process.
Thanks.

[MarekR22]

did you tried setVersion like I suggested in post #2?