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- [/
- Copyright 2007 John Maddock.
- Distributed under the Boost Software License, Version 1.0.
- (See accompanying file LICENSE_1_0.txt or copy at
- http://www.boost.org/LICENSE_1_0.txt).
- ]
- [section:is_abstract is_abstract]
- template <class T>
- struct is_abstract : public __tof {};
-
- __inherit If T is a (possibly cv-qualified) abstract type then inherits from
- __true_type, otherwise inherits from __false_type.
- __std_ref 10.3.
- __header ` #include <boost/type_traits/is_abstract.hpp>` or ` #include <boost/type_traits.hpp>`
- __compat The compiler must support DR337 (as of April 2005: GCC 3.4, VC++ 7.1 (and later),
- Intel C++ 7 (and later), and Comeau 4.3.2).
- Otherwise behaves the same as __is_polymorphic;
- this is the "safe fallback position" for which polymorphic types are always
- regarded as potentially abstract. The macro BOOST_NO_IS_ABSTRACT is used to
- signify that the implementation is buggy, users should check for this in their
- own code if the "safe fallback" is not suitable for their particular use-case.
- __examples
- [:Given: `class abc{ virtual ~abc() = 0; };` ]
- [:`is_abstract<abc>` inherits from `__true_type`.]
- [:`is_abstract<abc>::type` is the type `__true_type`.]
- [:`is_abstract<abc const>::value` is an integral constant
- expression that evaluates to /true/.]
- [:`is_abstract<T>::value_type` is the type `bool`.]
- [endsect]
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