Detailed Description

Definitions for the default help formatter.

The declarations live in the formatter_fwd partition; the bodies are here because they need the full definitions of cli::app_t and cli::option_t, which would otherwise form a cycle.

The page is assembled from the bottom up: cli::formatter_t::make_option renders one entry, cli::formatter_t::make_group renders a labelled block of them, and cli::formatter_t::make_help stitches together the usage line, description, groups, subcommands, and footer. Overriding any one of them replaces just that piece.