def run_other; end
def run_sweep; end
def run_then; end
def run_else; end
def run_a; end
def run_b; end
def run_inner; end

# Each branch holds one statement, so each branch is the value.
def single_statement_if(fast)
  run = if fast
    method(:run_then)
  else
    method(:run_else)
  end
  run.call
end

# The `then` branch evaluates to 0; `h` is only read by an inner statement,
# so it must not flow into `run`. The single-statement `else` still does.
def statement_if(fast)
  h = method(:run_other)
  run = if fast
    g = h
    0
  else
    method(:run_sweep)
  end
  run.call
end

# The multi-statement `elsif` branch is skipped; the branches on either side
# of it still flow, and nothing inside it does.
def elsif_chain(a, b)
  h = method(:run_inner)
  run = if a then method(:run_a) elsif b then g = h; 0 else method(:run_b) end
  run.call
end