What do you think about transpiling fut to C?

[ghost]

C++20 is a pretty high requirement that can't be met on some legacy systems stuck with old compilers. This is when C comes to the rescue as you said the generated C code need at most C11 and C11 is widely supported now.

[pfusik]

Support for legacy systems is not my priority.
There's some work that would be needed in the C backend, such as runtime type checking (dynamic_cast in C++).