boost::urls::grammar::is_charset

Alias for std::true_type if T satisfies CharSet .

Synopsis

Declared in header <boost/url/grammar/charset.hpp>

template<class T>
using is_charset = see-below;

Description

This metafunction determines if the type T meets these requirements of CharSet :

  • An instance of T is invocable with this equivalent function signature:

bool T::operator()( char ) const noexcept;

Example

Use with enable_if on the return value:

template< class CharSet >
typename std::enable_if< is_charset<T>::value >::type
func( CharSet const& cs );