multiset::multiset
Constructs a multiset that is empty or that is a copy of all or part of some other multiset.
multiset( );
explicit multiset (
const Compare& _Comp
);
multiset (
const Compare& _Comp,
const Allocator& _Al
);
multiset(
const multiset& _Right
);
template<class InputIterator>
multiset (
InputIterator _First,
InputIterator _Last
);
template<class InputIterator>
multiset (
InputIterator _First,
InputIterator _Last,
const Compare& _Comp
);
template<class InputIterator>
multiset (
InputIterator _First,
InputIterator _Last,
const Compare& _Comp,
const Allocator& _Al
);
multiset(
multiset&& _Right
);
Parameters
Parameter |
Description |
_Al |
The storage allocator class to be used for this multiset object, which defaults to Allocator. |
_Comp |
The comparison function of type const Compare used to order the elements in the multiset, which defaults to Compare. |
_Right |
The multiset of which the constructed multiset is to be a copy. |
_First |
The position of the first element in the range of elements to be copied. |
_Last |
The position of the first element beyond the range of elements to be copied. |
Remarks
All constructors store a type of allocator object that manages memory storage for the multiset and that can later be returned by calling get_allocator. The allocator parameter is often omitted in the class declarations and preprocessing macros used to substitute alternative allocators.
All constructors initialize their multiset.
All constructors store a function object of type Compare that is used to establish an order among the keys of the multiset and that can later be returned by calling key_comp.
The first three constructors specify an empty initial multiset, the second specifying the type of comparison function (_Comp) to be used in establishing the order of the elements and the third explicitly specifying the allocator type (_Al) to be used. The keyword explicit suppresses certain kinds of automatic type conversion.
The fourth constructor specifies a copy of the multiset _Right.
The next three constructors copy the range [_First, _Last) of a multiset with increasing explicitness in specifying the type of comparison function and allocator.
The last constructor specifies a copy of the multiset by moving _Right.
Example
// multiset_ctor.cpp
// compile with: /EHsc
#include <set>
#include <iostream>
int main( )
{
using namespace std;
multiset <int>::iterator ms1_Iter, ms2_Iter, ms3_Iter;
multiset <int>::iterator ms4_Iter, ms5_Iter, ms6_Iter, ms7_Iter;
// Create an empty multiset ms0 of key type integer
multiset <int> ms0;
// Create an empty multiset ms1 with the key comparison
// function of less than, then insert 4 elements
multiset <int, less<int> > ms1;
ms1.insert( 10 );
ms1.insert( 20 );
ms1.insert( 20 );
ms1.insert( 40 );
// Create an empty multiset ms2 with the key comparison
// function of geater than, then insert 2 elements
multiset <int, greater<int> > ms2;
ms2.insert( 10 );
ms2.insert( 20 );
// Create a multiset ms3 with the
// allocator of multiset ms1
multiset <int>::allocator_type ms1_Alloc;
ms1_Alloc = ms1.get_allocator( );
multiset <int> ms3( less<int>( ), ms1_Alloc );
ms3.insert( 30 );
// Create a copy, multiset ms4, of multiset ms1
multiset <int> ms4( ms1 );
// Create a multiset ms5 by copying the range ms1[_First, _Last)
multiset <int>::const_iterator ms1_bcIter, ms1_ecIter;
ms1_bcIter = ms1.begin( );
ms1_ecIter = ms1.begin( );
ms1_ecIter++;
ms1_ecIter++;
multiset <int> ms5( ms1_bcIter, ms1_ecIter );
// Create a multiset ms6 by copying the range ms4[_First, _Last)
// and with the allocator of multiset ms2
multiset <int>::allocator_type ms2_Alloc;
ms2_Alloc = ms2.get_allocator( );
multiset <int> ms6( ms4.begin( ), ++ms4.begin( ), less<int>( ), ms2_Alloc );
cout << "ms1 =";
for ( ms1_Iter = ms1.begin( ); ms1_Iter != ms1.end( ); ms1_Iter++ )
cout << " " << *ms1_Iter;
cout << endl;
cout << "ms2 = " << *ms2.begin( ) << " " << *++ms2.begin( )
<< endl;
cout << "ms3 =";
for ( ms3_Iter = ms3.begin( ); ms3_Iter != ms3.end( ); ms3_Iter++ )
cout << " " << *ms3_Iter;
cout << endl;
cout << "ms4 =";
for ( ms4_Iter = ms4.begin( ); ms4_Iter != ms4.end( ); ms4_Iter++ )
cout << " " << *ms4_Iter;
cout << endl;
cout << "ms5 =";
for ( ms5_Iter = ms5.begin( ); ms5_Iter != ms5.end( ); ms5_Iter++ )
cout << " " << *ms5_Iter;
cout << endl;
cout << "ms6 =";
for ( ms6_Iter = ms6.begin( ); ms6_Iter != ms6.end( ); ms6_Iter++ )
cout << " " << *ms6_Iter;
cout << endl;
// Create a set by moving s5
set<int> ms7(move(ms5));
cout << "ms7 =";
for ( ms7_Iter = ms7.begin( ); ms7_Iter != ms7.end( ); ms7_Iter++ )
cout << " " << *ms7_Iter;
cout << endl;
}
Output
ms1 = 10 20 20 40
ms2 = 20 10
ms3 = 30
ms4 = 10 20 20 40
ms5 = 10 20
ms6 = 10
ms7 = 10 20
Requirements
Header: <set>
Namespace: std