example of a meager set

Note that $\mathbb{Q}$ is meager in $ℝ$ under the usual topology. Let ${\{r_n\}}_{n\in \mathbb{N}}$ be an enumeration of $\mathbb{Q}$. Then $\mathbb{Q}={\displaystyle \bigcup _{n\in \mathbb{N}}}\{r_n\}$ and, for every $n\in \mathbb{N}$, $\mathrm{int}\overline{\{r_n\}}=\mathrm{int}\{r_n\}=\mathrm{\varnothing }$.