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Macro BOOST_TYPE_ERASURE_MEMBER

BOOST_TYPE_ERASURE_MEMBER — Defines a primitive concept for a member function.

Synopsis

// In header: <boost/type_erasure/member.hpp>

BOOST_TYPE_ERASURE_MEMBER(concept_name, member)

Description

The declaration of the concept is

template<class Sig, class T = _self>
struct concept_name;

where Sig is a function type giving the signature of the member function, and T is the object type. T may be const-qualified for const member functions. concept_name<R(A...) const, T> is an alias for concept_name<R(A...), const T>.

This macro can only be used at namespace scope.

Example:

namespace boost {
BOOST_TYPE_ERASURE_MEMBER(push_back)
}
typedef boost::has_push_back<void(int)> push_back_concept;

The concept defined by this function may be specialized to provide a concept_map. The class object will be passed by reference as the first parameter.

template<>
struct has_push_back<void(int), std::list<int> > {
  static void apply(std::list<int>& l, int i) { l.push_back(i); }
};

In C++03, the macro can only be used in the global namespace and is defined as:

#define BOOST_TYPE_ERASURE_MEMBER(qualified_name, member, N)

Example:

BOOST_TYPE_ERASURE_MEMBER((boost)(has_push_back), push_back, 1)
typedef boost::has_push_back<void(int), _self> push_back_concept;

For backwards compatibility, this form is always accepted.

Parameters:

concept_name

is the name of the concept to declare. If it is omitted it defaults to has_ ## member

member

is the name of the member function.


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