Function common 

pub fn common(
    page_title: &str,
    description: &str,
    keywords: Option<&[&str]>,
    author: Option<&str>,
    viewport: &str,
    robots: &str,
) -> Vec<Element>

The common <meta> block: charset, viewport, description, robots, keywords, author — plus the <title>.

A bug fixed in the port

Winged-Swift’s SEO.common(title:…) accepts a title argument and never uses it — no <title> element is emitted. This version emits one. See PORTING.md.