Synopsis

template<
      template< typename P1 > class F
    , typename Tag = |unspecified|
    >
struct quote1
{
    // |unspecified|
    // |...|
};
|...|
template<
      template< typename P1,|...| typename Pn > class F
    , typename Tag = |unspecified|
    >
struct quoten
{
    // |unspecified|
    // |...|
};

Description

quoten is a higher-order primitive that wraps an n-ary |Metafunction| to create a corresponding |Metafunction Class|.

Header

#include <boost/mpl/quote.hpp>

Model of

|Metafunction Class|

Parameters

Expression semantics

For any n-ary |Metafunction| f and arbitrary type tag:

typedef quoten<f> g;
typedef quoten<f,tag> g;

struct g
{
    template< typename A1,|...| typename An > struct apply
        : f<A1,|...|An>
    {
    };
};

struct g
{
    template< typename A1,|...| typename An > struct apply
    {
        typedef f<A1,|...|An> type;
    };
};

Example

template< typename T > struct f1
{
    typedef T type;
};
template<
    typename T1, typename T2, typename T3, typename T4, typename T5
    >
struct f5
{
    // no 'type' member!
};
typedef quote1<f1>::apply<int>::type t1;
typedef quote5<f5>::apply<char,short,int,long,float>::type t5;
BOOST_MPL_ASSERT(( is_same< t1, int > ));
BOOST_MPL_ASSERT(( is_same< t5, f5<char,short,int,long,float> > ));

See also

|Composition and Argument Binding|, |Invocation|, |bind|, |lambda|, |protect|, |apply|