TOC in output: html_document of R markdown -

table of contents (toc) options in metadata section of r markdown not work. here mwe. not produce toc. how can fix it?

--- title: "my study" author: "my name" date: "february 4, 2016" output: html_document toc: true toc_depth: 2 toc_float: true ---  # section 1. executive # section 2. introduction # section 3. conclusion 

the rmarkdown documentation specifies toc options should nested in output format in yaml front matter. following code produces expected output:

--- title: "my study" author: "my name" date: "february 4, 2016" output:    html_document:     toc: true     toc_depth: 2     toc_float: true ---