Only assigning to a __block variable in one of the blocks. I wish this was an error.

MissingAssignment.m

#import "Example.h" // https://gist.github.com/hborders/2af9b39e27b62ef9e68c65085126fe4a

- (void)missingAssignment {
  Example * _Nonnull fooExample = [[ExampleFoo alloc] initWithF:@"foo"
                                                              g:@"goo"];
  NSNumber * _Nonnull __block number;
  [fooExample switchFoo:^(ExampleFoo * _Nonnull foo_) {
    number = @(foo_.f.length + foo_.g.length);
  }
                    bar:^(ExampleBar * _Nonnull bar_) {
    // should be:
    // number = @(bar_.b.length + bar.c.length);
    @(bar_.b.length + bar.c.length);
  }];
}