[depr.format]

# Annex D (normative) Compatibility features [[depr]](./#depr)

## D.20 Deprecated formatting [depr.format]

### [D.20.1](#syn) Header <format> synopsis [[depr.format.syn]](depr.format.syn)

[1](#syn-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/future.tex#L750)

The header [<format>](format.formatter.spec#header:%3cformat%3e "28.5.6.4 Formatter specializations [format.formatter.spec]") has the following additions:

namespace std {template<class Visitor, class Context>decltype(auto) visit_format_arg(Visitor&& vis, basic_format_arg<Context> arg);}

### [D.20.2](#arg) Formatting arguments [[depr.format.arg]](depr.format.arg)

[🔗](#lib:visit_format_arg)

`template<class Visitor, class Context>
  decltype(auto) visit_format_arg(Visitor&& vis, basic_format_arg<Context> arg);
`

[1](#arg-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/future.tex#L769)

*Effects*: Equivalent to: return visit(std​::​forward<Visitor>(vis), arg.value);