tests/cases/compiler/numericIndexerConstraint.ts(2,5): error TS2412: Property '0' of type 'number' is not assignable to numeric index type 'RegExp'. ==== tests/cases/compiler/numericIndexerConstraint.ts (1 errors) ==== class C { 0: number; ~~~~~~~~~~ !!! error TS2412: Property '0' of type 'number' is not assignable to numeric index type 'RegExp'. [x: number]: RegExp; }