Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of boost. Click here for the latest Boost documentation.
PrevUpHomeNext

Macro BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE

BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE — A macro which expands to a metafunction which tests whether an inner member function template or static member function template with a particular name exists.

Synopsis

// In header: <boost/tti/has_function_template.hpp>

BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE(trait, name, ...)

Description

BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE is a macro which expands to a metafunction. The metafunction tests whether an inner member function template or static member function template with a particular name exists. The macro takes the form of BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE(trait,name,...) where

trait = the name of the metafunction
name = inner member function template or static member function template name
... = variadic parameters.

The variadic parameter(s) are either:

A sequence of valid instantiations for the static member function template parameters ie. 'int,long,double' etc.

or

A single variadic parameter which is a Boost PP array whose elements are a sequence of valid instantiations for the static member function template parameters ie. '(3,(int,long,double))' etc. This form is allowed in order to be compatible with using the non-variadic form of this macro.

BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE generates a metafunction called "trait" where 'trait' is the first macro parameter.

template<class BOOST_TTI_TP_T,class BOOST_TTI_R,class BOOST_TTI_FS,class BOOST_TTI_TAG>
struct trait
  {
  static const value = unspecified;
  typedef mpl::bool_<true-or-false> type;
  };

The metafunction types and return:

  BOOST_TTI_TP_T   = the enclosing type in which to look for our 'name'.
                     The enclosing type can be a class, struct, or union.
  
  BOOST_TTI_TP_R   = the return type of the function template
                     in a single instantiation of the function template
  
  BOOST_TTI_TP_FS  = (optional) the parameters of the function template as a boost::mpl forward sequence
                     if the function template parameters are not empty. These parameters are a single
                     instantiation of the function template.
  
  BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function template
                     if a tag is needed.
  
  returns = 'value' is true if the 'name' exists, 
            with the appropriate member function template or static member function template type,
            otherwise 'value' is false.


PrevUpHomeNext