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Coding Standards
Front Page / Sequences / Intrinsic Metafunctions / erase |
template< typename Sequence , typename First , typename Last = unspecified > struct erase { typedef unspecified type; };
erase performs a removal of one or more adjacent elements in the sequence starting from an arbitrary position.
#include <boost/mpl/erase.hpp>
Parameter | Requirement | Description |
---|---|---|
Sequence | Extensible Sequence or Extensible Associative Sequence | A sequence to erase from. |
First | Forward Iterator | An iterator to the beginning of the range to be erased. |
Last | Forward Iterator | An iterator past-the-end of the range to be erased. |
For any Extensible Sequence s, and iterators pos, first and last into s:
typedef erase<s,first,last>::type r;
Return type: | Extensible Sequence. |
---|---|
Precondition: | [first,last) is a valid range in s. |
Semantics: | r is a new sequence, concept-identical to s, of the following elements: [begin<s>::type, pos), [last, end<s>::type). |
Postcondition: | The relative order of the elements in r is the same as in s; size<r>::value == size<s>::value - distance<first,last>::value |
typedef erase<s,pos>::type r;
Return type: | Extensible Sequence. |
---|---|
Precondition: | pos is a dereferenceable iterator in s. |
Semantics: | Equivalent to typedef erase< s,pos,next<pos>::type >::type r; |
For any Extensible Associative Sequence s, and iterator pos into s:
typedef erase<s,pos>::type r;
Return type: | Extensible Sequence. |
---|---|
Precondition: | pos is a dereferenceable iterator to s. |
Semantics: | Erases the element at a specific position pos; equivalent to erase_key<s, deref<pos>::type >::type. |
Postcondition: | size<r>::value == size<s>::value - 1. |
Sequence archetype | Complexity (the range form) |
---|---|
Extensible Associative Sequence | Amortized constant time. |
Extensible Sequence | Quadratic in the worst case, linear at best. |
typedef vector_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; BOOST_MPL_ASSERT_RELATION( size<result>::value, ==, 7 ); typedef find<result, integral_c<int,7> >::type iter; BOOST_MPL_ASSERT(( is_same< iter, end<result>::type > ));