What should I use in Qt?

So I have downloaded the latest version of Qt Creator (5.something...) using the online Qt Downloader, and GMP version 6.2.0

But I can't find any tutorials on how to use GMP library at all. And if I do, it's on Mac/Linux, which I can't use. It's unlike in python where we put the library folder in the working directory and it's done :\

So, how can I write a "Hello world" program using GMP in Qt Creator? A program that calculates 10000!, or e^1000 to 10^4 decimal places, for example.

Thank you for reading.

Edit: actually I don't need to use GMP, any high-precision float library is okay. What should I use in Qt? Thank you.

Qt Creator is simply a code development IDE designed for developing Qt applications. It is not Qt, which is a set of libraries for abstracting graphics and operating system details to allow writing applications in an operating system independent way.

If you want to develop applications with Qt Creator, you need to configure a toolchain: compiler, linker, debugger, etc. On Windows, Visual C++ or GCC are the most commonly used. If you have not done this, then you should start with the Qt Creator documentation. If you want to develop Qt applications, you'll also need to install Qt and configure Qt Creator to use it.

If you want to use an external (non-Qt) library in a Qt application, then you will need to add it to your project configuration (cmake or qmake). This is also described in the documentation.

Since GMP is mostly designed for use on a linux/Mac PC, you will probably have to build it yourself from the source code if you want to use it on Windows. From looking at the source code, that is a big job and off topic for this forum. If you search hard, you might be able to find a site with a pre-built Windows binary.