The C++ standard for the F-35 Fighter Jet [video]

The same is true for the software that runs many satellites. Use of the STL is prohibited.

The main issue is mission assurance. Using the stack or the heap means your variables aren't always at the same memory address. This can be bad if a particular memory cell has failed. If every variable has a fixed address, and one of those addresses goes bad, a patch can be loaded to move that address and the mission can continue.

> Using the stack or the heap means your variables aren't always at the same memory address

Where do you place the variables then? as global variables? and how do you detect if a memory cell has gone bad?

your programs have a data segment. its not the heap nor the stack... and it can be (depending on loader/linker) a source of reliable object->address mappings as its not dynamically populated.

That sounds like your answer is: "Yes, global variables".

That may be a perfectly good solution in many embedded environments, but in most other context's global variables are considered bad design or very limiting and impractical.