Front Page / Sequences / Classes / range_c

# range_c

### Synopsis

    template<
          typename T
        , T Start
        , T Finish
        >
    struct range_c
    {
        typedef integral_c<T,Start> start;
        typedef integral_c<T,Finish> finish;
        // unspecified
        // ...
    };

### Description

`range_c` is a sorted Random Access Sequence of Integral Constants. Note that because it is not an Extensible Sequence, sequence-building intrinsic metafunctions such as `push_front` and transformation algorithms such as `replace` are not directly applicable — to be able to use them, you'd first need to copy the content of the range into a more suitable sequence.

### Header

    #include <boost/mpl/range_c.hpp>

### Model of

Random Access Sequence

### Expression semantics

In the following table, `r` is an instance of `range_c`, `n` is an Integral Constant, `T` is an arbitrary integral type, and `n` and `m` are integral constant values of type `T`.

Expression | Semantics
--- | ---
    range_c<T,n,m>
    range_c<T,n,m>::type
| A sorted Random Access Sequence of integral constant wrappers for the half-open range of values [`n`, `m`): `integral_c<T,n>`, `integral_c<T,n+1>`,... `integral_c<T,m-1>`.
`begin<r>::type` | An iterator pointing to the beginning of `r`; see Random Access Sequence.
`end<r>::type` | An iterator pointing to the end of `r`; see Random Access Sequence.
`size<r>::type` | The size of `r`; see Random Access Sequence.
`empty<r>::type` | A boolean Integral Constant `c` such that `c::value == true` if and only if `r` is empty; see Random Access Sequence.
`front<r>::type` | The first element in `r`; see Random Access Sequence.
`back<r>::type` | The last element in `r`; see Random Access Sequence.
`at<r,n>::type` | The `n`th element from the beginning of `r`; see Random Access Sequence.

### Example

    typedef range_c<int,0,0> range0;
    typedef range_c<int,0,1> range1;
    typedef range_c<int,0,10> range10;

    BOOST_MPL_ASSERT_RELATION( size<range0>::value, ==, 0 );
    BOOST_MPL_ASSERT_RELATION( size<range1>::value, ==, 1 );
    BOOST_MPL_ASSERT_RELATION( size<range10>::value, ==, 10 );

    BOOST_MPL_ASSERT(( empty<range0> ));
    BOOST_MPL_ASSERT_NOT(( empty<range1> ));
    BOOST_MPL_ASSERT_NOT(( empty<range10> ));

    BOOST_MPL_ASSERT(( is_same< begin<range0>::type, end<range0>::type > ));
    BOOST_MPL_ASSERT_NOT(( is_same< begin<range1>::type, end<range1>::type > ));
    BOOST_MPL_ASSERT_NOT(( is_same< begin<range10>::type, end<range10>::type > ));

    BOOST_MPL_ASSERT_RELATION( front<range1>::type::value, ==, 0 );
    BOOST_MPL_ASSERT_RELATION( back<range1>::type::value, ==, 0 );
    BOOST_MPL_ASSERT_RELATION( front<range10>::type::value, ==, 0 );
    BOOST_MPL_ASSERT_RELATION( back<range10>::type::value, ==, 9 );

### See also

Sequences, Random Access Sequence, vector_c, set_c, list_c