[inkyoto]

C++ templates are unwound at the compile time before the «expanded» template code passes along into the optimiser where most of the unused code is elided.

Unless the templates have been externalised (i.e. defined as «extern template …», of course). Even then, a modern compiler+linker combo will optimise most of the unused code away at the linking time thus reducing the final binary size. I do understand that the LTO might not be available for every embedded platform, though.

P.S. That is exactly the point of the C++ template metaprogramming – the hard lifting is delegated to the compiler, which leads to increased compile times but also to more efficient and very compact runtime code.