single_view

Synopsis

template<
      typename T
    >
struct single_view
{
    // unspecified
    // ...
};

Description

A view onto an arbitrary type T as on a single-element sequence.

Header

#include <boost/mpl/single_view.hpp>

Model of

Random Access Sequence

Parameters

Parameter	Requirement	Description
`T`	Any type	The type to be wrapped in a sequence.

Expression semantics

The semantics of an expression are defined only where they differ from, or are not defined in Random Access Sequence.

In the following table, v is an instance of single_view, x is an arbitrary type.

Expression	Semantics
single_view<x> single_view<x>::type	A single-element Random Access Sequence `v` such that `front<v>::type` is identical to `x`.
`size<v>::type`	The size of `v`; `size<v>::value == 1`; see Random Access Sequence.

Example

typedef single_view<int> view;
typedef begin<view>::type first;
typedef end<view>::type last;

BOOST_MPL_ASSERT(( is_same< deref<first>::type,int > ));
BOOST_MPL_ASSERT(( is_same< next<first>::type,last > ));
BOOST_MPL_ASSERT(( is_same< prior<last>::type,first > ));

BOOST_MPL_ASSERT_RELATION( size<view>::value, ==, 1 );

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