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.

erase

Synopsis

template<
      typename Sequence
    , typename First
    , typename Last = typename First::next
    >
struct erase
{
    typedef unspecified type;
};

Description

erase performs a removal of one or several consequent elements in the sequence starting from an arbitrary position. The algorithm returns a new sequence which contains all the elements in the ranges [begin<Sequence>::type, First) and [Last, end<Sequence>::type). The result sequence preserves all the functional and performance characteristics of the original Sequence, except its size and identity.

Definition

#include "boost/mpl/erase.hpp"

Parameters

Parameter	Requirement	Description	Default value
`Sequence`	A model of Extensible Sequence	A sequence to handle the erase operation.
`First`	A model of Forward Iterator	Iterator to the beginning of the range to be erased.
`Last`	A model of Forward Iterator	Past-the-end iterator of the range to be erased.	`typename First::next`

Expression semantics

Expression Expression type Precondition Semantics Postcondition

typedef erase<Sequence,pos>::type s; A model of Extensible Sequence pos is a dereferenceable iterator in Sequence. Returns a new sequence which contains all the elements in the ranges [begin<Sequence>::type, pos) and [next<pos>::type, end<Sequence>::type). size<s>::type::value == size<Sequence>::type::value - 1; the relative order of the elements in s is the same as in Sequence.

typedef erase<Sequence,first,last>::type s; A model of Extensible Sequence [first,last) is a valid range in Sequence. Returns a new sequence which contains all the elements in the ranges [begin<Sequence>::type, first) and [last, end<Sequence>::type). size<s>::type::value == size<Sequence>::type::value - distance<first,last>::type::value; the relative order of the elements in s is the same as in Sequence.

Expression	Expression type	Precondition	Semantics	Postcondition
`typedef erase<Sequence,pos>::type s;`	A model of Extensible Sequence	`pos` is a dereferenceable iterator in `Sequence`.	Returns a new sequence which contains all the elements in the ranges `[begin<Sequence>::type, pos)` and `[next<pos>::type, end<Sequence>::type)`.	`size<s>::type::value == size<Sequence>::type::value - 1`; the relative order of the elements in `s` is the same as in `Sequence`.
`typedef erase<Sequence,first,last>::type s;`	A model of Extensible Sequence	`[first,last)` is a valid range in `Sequence`.	Returns a new sequence which contains all the elements in the ranges `[begin<Sequence>::type, first)` and `[last, end<Sequence>::type)`.	`size<s>::type::value == size<Sequence>::type::value - distance<first,last>::type::value`; the relative order of the elements in `s` is the same as in `Sequence`.

Complexity

The range form has linear complexity. The complexity of single-element erase is sequence dependent (linear in the worst case, or amortized constant time).

Example

typedef list_c<int,1,0,5,1,7,5,0,5> values;
typedef find< values, integral_c<int,7> >::type pos;
typedef erase<values,pos>::type result_seq;
BOOST_STATIC_ASSERT(size<result_seq>::type::value == 7);

typedef find<result, integral_c<int,7> >::type result_iter;
BOOST_MPL_ASSERT_IS_SAME(result_iter, end<result_seq>::type);

Boost C++ Libraries

erase

Synopsis

Description

Definition

Parameters

Expression semantics

Complexity

Example

See also