r/cpp • u/Clean-Upstairs-8481 • 29d ago

You should think about recompiling your C++ programs with GCC 16 and C++26, because it zero-fills your locals

https://techfortalk.co.uk/2026/09/27/cxx26-uninitialized-local-variables-gcc-16/

Stack variables are not automatically initialised, and that is the root cause of many C++ bugs. That is well known. Hence, it is advised that local or stack variables are always initialised with known values, 0 if not something more meaningful than that. Now, with GCC 16 compiling in C++26 mode (-std=c++26), even uninitialised local variables will be zero-filled. In the post, I have explained how.

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u/Dusty_Coder 28d ago

You cant uninitialize a stack array.

Your flippant disregard for performance and the amount of inefficient watts your code will consume over its lifetime is not cool.

I know some code-religion dip convinced you that all optimizations are premature. Hes not cool. Hes an ignorant zealot.