value::as_string (2 of 3 overloads)

Return a reference to the underlying string, or throw an exception.

string const&
as_string(
    boost::source_location const& loc = BOOST_CURRENT_LOCATION) const&;

If is_string() is true, returns a reference to the underlying string, otherwise throws an exception.

Strong guarantee.

Type	Thrown On
boost::system::system_error	`! this->is_string()`.

Name	Description
`loc`	`source_location` to use in thrown exception; the source location of the call site by default.

Constant.