[Development] Question about QCoreApplicationData::*_libpaths

Knoll Lars Lars.Knoll at theqtcompany.com
Tue Jan 19 09:39:02 CET 2016

On 15/01/16 23:20, "Development on behalf of Thiago Macieira" <development-bounces at qt-project.org on behalf of thiago.macieira at intel.com> wrote:

>On Friday 15 January 2016 18:42:43 Marc Mutz wrote:
>> And you will see it over and over again until enough people are fixing 
>> premature pessimisations in existing Qt code. There's a notable increase 
>> already. But it takes a long time to turn a supertanker around...
>Some of us call them "trade-offs". Every trade-off is a pessimisation 
>somewhere for an optimisation somewhere else. Often, they're not measured in 
>the same units or not quantifiable at all.
>API quality and consistency fall under those definitions.

Exactly this. 

>> And no, I cannot believe that using the Qt containers leads to faster
>> applications. It may lead to applications faster, but not to faster
>> applications.
>Exactly. TTM is a significant factor and we all know Paretto's Law (80-20 

And this. Let’s not forget to ask ourselves the question why many developers use Qt in C++ development, often even in the case where they don’t need a UI. For the past 20 years a lot of our focus has been on making development easy, and creating APIs that serve that goal. This means that we are in many case optimising for TTM more than for ultimate speed.

I think we agree that std containers are in many cases faster than the Qt containers. But they are harder to use and especially developers that come from other languages often appreciate the ease of use of the Qt containers. 

The main question IMO is how we can bring these two worlds closer together for Qt 6 (or maybe even to some extent in Qt 5.x). 


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