This presupposes that you're doing string manipulation and raw memory moves. I don't know about other people's code, but in my own experience neither of those things are likely to be happening in embedded code. You're much more likely to pre-allocate all your memory, and use zero-copy patterns where ever possible. I never used a C-string in relation to talking to peripherals (i2c, spi, register mapped) or when doing dsp. Moreover, if you do need to use memcpy it's probably because you are doing something very low level for which memcpy is the best choice.