Function chart_html_placed 

pub fn chart_html_placed<'a>(
    chart: &Chart<'_>,
    bars: impl IntoIterator<Item = Bar<'a>>,
    opts: &Emit,
    out: &mut String,
    placed: &mut Vec<Range<usize>>,
)

A chart, saying where each bar landed.

Byte-identical to chart_html_into, and it appends one entry to placed per bar, in order: the offsets in out between which that bar’s whole column was written. See crate::list::cells_html_placed, which exists for the same reason and says it at length: a caller compiling this markup into a template has to know which bytes one bar produced, and the writer is the only source for that which cannot be wrong.