Using C++ in an embedded environment

Question

Today I got into a very interesting conversation with a coworker, of which one subject got me thinking and googling this evening. Using C++ (as opposed to C) in an embedded

Answer 1

It sort of depends on the particular nature of your embedded system and which features of C++ you use. The language itself doesn't necessarily generate bulkier code than C.

For example, if memory is your tightest constraint, you can just use C++ like "C with classes" -- that is, only using direct member functions, disabling RTTI, and not having any virtual functions or templates. That will fit in pretty much the same space as the equivalent C code, since you've no type information, vtables, or redundant functions to clutter things up.

I've found that templates are the biggest thing to avoid when memory is really tight, since you get one copy of each template function for each type it's specialized on, and that can rapidly bloat code segment.

In the console video games industry (which is sort of the beefy end of the embedded world) C++ is king. Our constraints are hard limits on memory (512mb on current generation) and realtime performance. Generally virtual functions and templates are used, but not exceptions, since they bloat the stack and are too perf-costly. In fact, one major manufacturer's compiler doesn't even support exceptions at all.