I observed some unclear behaviour in a C programm compiled with GCC. Could anymone explain why there is a difference in the following code

I was looking at the code generated when I use std::bit_cast to convert from arrays of a user-defined strong type to the underlying type and noticed that GCC seems to emit some code even at high optimization levels. For

I was trying to install GROMACS following the installation guide from the GROMACS webpage (https://manual.gromacs.org/documentation/2024.2/install-guide/index.html) but after running:

I have this c code:

I have been trying to run a c code from my terminal. The command:

I was checking library function isupper() to check if the function version or macro version of
isupper() is efficient depending on storage used or runtime and I have this peculiar problem
when using scanf() for storing input character to a int varibale.
Here is my code-

I’ve been having trouble for hours now while trying to compare 2 seemingly identical structs. I’ve looked into alignment and padding as possible issues but found no issues. When I played around with different combinations of designated initialisation and zero initialisation combined with strcpy() I found that memcpy() returned either 1 or 0. I hope I’ve finally narrowed down the problem into a single C file.

I have the following code that compiles fine on GCC 13.2. Colleagues can’t compile it on GCC 13.1. The new version compiles fine even with -Wall -Wextra. I assume that GCC 13.2 is better and more correct. Which change made this possible? Why is this call not ambiguous when it was considered ambiguous before?

I had a class like this:

I have a warning I don’t understand in a templated function. How can the value be not initialized if its the if condition?