Method swap

common/expr.h:321–326

  ABSL_MUST_USE_RESULT std::vector<Expr> release_args();

  friend void swap(CallExpr& lhs, CallExpr& rhs) noexcept {
    using std::swap;
    swap(lhs.function_, rhs.function_);
    swap(lhs.target_, rhs.target_);
    swap(lhs.args_, rhs.args_);
  }

 private:
  friend class Expr;