I am getting following warnings for code:

QRect rct ( 0, 0, rect().width(), rect().height() );
warning: passing `qreal' for converting 3 of `QRect::QRect(int, int, int, int)'
warning: passing `qreal' for converting 4 of `QRect::QRect(int, int, int, int)'

I googled it, but haven't found much. How to avoid this warning?

Thanks for you time.

3

2 Answers

It appears that rect() returns a QRectF, and you want to convert it to QRect. You have two options:

• QRectF::toRect (discarded decimal part)
• QRectF::toAlignedRect (rounded).

1

I don't have enough reputation to comment, so I'll have to ammend LogicStuff's reply. Our answers have different interpretation of the documentation so please check for yourselves, and I am happy to delete this if I am wrong.

It appears that rect() returns a QRectF, and you want to convert it to QRect. You have two options:

• QRectF::toRect (rounded to nearest integer)
• QRectF::toAlignedRect (Bounding box, smallest integer rectangle containing the desired QRectF).

toRect

E.g. for precision drawing something that looks accurate

toAlignedRect

E.g. for ensuring that you don't omit a line of pixels when drawing something.

For example, 1/3 in binary is 0.0101010101010101010101...so depending on how you calculate one and a half thirds, you may get a half, represented as either0.10000000000000000... or 0.0111111111111... and maybe round it up calculating one way and down calculating it another. It would then be unfortunate if you drew the edge of a feature (calculated one way) and neglected to erase a row of pixels when wiping the slate clear using a rectangle calculated another way. My calculation example may be wrong, but it's only meant to be illustrative.

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