What are the 'use memo' and 'use no memo' directives in React Compiler?

Direct answer

'use memo' explicitly opts a function into compiler optimization in configurations where that matters, while 'use no memo' opts a function out and should usually be treated as a targeted escape hatch.

Directive	Purpose	Typical use
"use memo"	Request compiler optimization for the function/module	Annotation or incremental adoption strategies
"use no memo"	Prevent compiler optimization	Temporary compatibility or debugging escape hatch

compiler-directives.jsx

function LegacyGrid() {
  "use no memo";

  return <ThirdPartyGrid />;
}

function OptimizedPanel() {
  "use memo";

  return <ExpensivePanel />;
}