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[Home]equal

Synopsis

template<
      typename Sequence1
    , typename Sequence2
    , typename Pred = is_same<_1,_2>
    >
struct equal
{
    typedef unspecified type;
};

Description

Returns true_ if the two sequences Sequence1 and Sequence2 are identical when compared element-by-element, and otherwise returns false_.

Definition

#include "boost/mpl/equal.hpp"

Parameters

 Parameter  Requirement  Description  
Sequence1, Sequence2A model of Forward SequenceSequences to compare.
PredA binary Predicate [Lambda Expression]The comparison metafunction.

Expression semantics

 Expression  Expression type  Precondition  Semantics  Postcondition 
typedef equal<Sequence1,Sequence2,Pred>::type c;A model of Integral Constantc::value == true is and only if size<Sequence1>::type::value == size<Sequence2>::type::value and for every iterator i in [begin<Sequence>::type,end<Sequence>::type) i::type is identical to advance< begin<Sequence2>::type, distance< begin<Sequence1>::type,i >::type >::type.

Complexity

Linear. At most size<Sequence1>::value comparisons.

Example

typedef vector<char,int,unsigned,long,unsigned long> s1;
typedef list<char,int,unsigned,long,unsigned long> s2;
BOOST_STATIC_ASSERT((equal<s1,s2>::type::value));

See also

Algorithms, count, count_if


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Last edited March 10, 2003 5:39 am