insert

Synopsis

template<
      typename Sequence
    , typename Pos
    , typename T
    >
struct insert
{
    typedef unspecified type;
};


template<
      typename Sequence
    , typename T
    >
struct insert
{
    typedef unspecified type;
};

Description

insert is an overloaded name:

insert<Sequence,Pos,T> performs an insertion of type T at an arbitrary position Pos in Sequence. Pos is ignored is Sequence is a model of Extensible Associative Sequence.
insert<Sequence,T> is a shortcut notation for insert<Sequence,Pos,T> for the case when Sequence is a model of Extensible Associative Sequence.

Header

#include <boost/mpl/insert.hpp>

Model of

Tag Dispatched Metafunction

Parameters

Parameter	Requirement	Description
`Sequence`	Extensible Sequence or Extensible Associative Sequence	A sequence to insert into.
`Pos`	Forward Iterator	An iterator in `Sequence` specifying the insertion position.
`T`	Any type	The element to be inserted.

Expression semantics

For any Extensible Sequence s, iterator pos in s, and arbitrary type x:

typedef insert<s,pos,x>::type r;

Return type:	Extensible Sequence
Precondition:	`pos` is an iterator in `s`.
Semantics:	`r` is a sequence, concept-identical to `s`, of the following elements: [`begin<s>::type`, `pos`), `x`, [`pos`, `end<s>::type`).
Postcondition:	The relative order of the elements in `r` is the same as in `s`. at< r, distance< begin<s>::type,pos >::type >::type is identical to `x`; size<r>::value == size<s>::value + 1;

For any Extensible Associative Sequence s, iterator pos in s, and arbitrary type x:

typedef insert<s,x>::type r;

Return type:	Extensible Associative Sequence
Semantics:	`r` is concept-identical and equivalent to `s`, except that `at< r, key_type<s,x>::type >::type` is identical to `value_type<s,x>::type`.
Postcondition:	`size<r>::value == size<s>::value + 1`.

typedef insert<s,pos,x>::type r;

Return type:	Extensible Associative Sequence
Precondition:	`pos` is an iterator in `s`.
Semantics:	Equivalent to `typedef insert<s,x>::type r`; `pos` is ignored.

Complexity

Sequence archetype	Complexity
Extensible Associative Sequence	Amortized constant time.
Extensible Sequence	Linear in the worst case, or amortized constant time.

Example

typedef vector_c<int,0,1,3,4,5,6,7,8,9> numbers;
typedef find< numbers,integral_c<int,3> >::type pos;
typedef insert< numbers,pos,integral_c<int,2> >::type range;

BOOST_MPL_ASSERT_RELATION( size<range>::value, ==, 10 );
BOOST_MPL_ASSERT(( equal< range,range_c<int,0,10> > ));

typedef map< mpl::pair<int,unsigned> > m;
typedef insert<m,mpl::pair<char,long> >::type m1;

BOOST_MPL_ASSERT_RELATION( size<m1>::value, ==, 2 );
BOOST_MPL_ASSERT(( is_same< at<m1,int>::type,unsigned > ));
BOOST_MPL_ASSERT(( is_same< at<m1,char>::type,long > ));