Comment by dspwizard

Cadence DSPs have C++17 compatible compiler and will be c++20 soon, new CEVA cores also (both are are clang based). TI C7x is still C++14 (C6000 is ancient core, yet still got c++14 support as you mentioned). AFIR Cadence ASIP generator will give you C++17 toolchain and c++20 is on roadmap, but not 100% sure.

But for those devices you use limited subset of language features and you would be better of not linking c++ stdlib and even c stdlib at all (so junior developers don't have space for doing stupid things ;))