A question about uint 8 and uint 16 and uint 32 and uint 64

[Radek]

(1) If you have replaced qint64 by qint32 then why have you done it? A 32-bit CPU can process 64-bit integers, too. Your (32-bit) Qt will take care for 64-bit arithmetic. No need for replacing qint64 by qint32.
(2) As to possible errors: Check line 193. I guess "duration" was a 64-bit integer. Because a 32-bit int can hold 4*10e9 at most, the "new Generator" will fail whenever duration > 4000 sec.

[wysota]

Because a 32-bit int can hold 4*10e9 at most, the "new Generator" will fail whenever duration > 4000 sec.

It is a signed integer so even only half of that.

[rezas1000]

A 32-bit CPU can process 64-bit integers

Not wrong???

[Radek]

Why should it be wrong? It's only a question of a bit of programming (multiple precision arithmetics).

[rezas1000]

My system is 32-bit.
64-bit applications will not run on my system.

So in the above code, why should we use qint64?

[wysota]

My system is 32-bit.
64-bit applications will not run on my system.

So in the above code, why should we use qint64?

quint64 is just a datatype (mapping to unsigned long long or something similar), it has nothing to do with the width of the address or data bus which is what makes a system "32 bit" or "64 bit". The processor can handle 32 bit as well as 64 bit datatypes and maybe even 128 bit types as well, it is just a matter of efficiency of processing such data.

[anda_skoa]

Exactly!

A "double" for example is always 64 bit, it is specified that way https://en.wikipedia.org/wiki/Double_precision

Cheers,
_