[derek]

It's certainly possible that these could be used in combination. GCC optimizations aren't significantly enhanced by JSDoc annotations, so presumably this could generate code for GCC to optimize without losing major benefits on either side.

The React.js team has been explicit about the library being GCC advanced mode compatible, so they certainly have awareness of its capabilities. Whether they are using them together internally or they use a different solution for tree shaking et al is another question.