The sample code below illustrates how to use the
list::assign, list::empty, and list::erase STL functions in Visual C++.
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Required Header
<list>
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Prototype
void assign(const_iterator first, const_iterator last);
void assign(size_type n, const T& x = T());
iterator erase(iterator it);
iterator erase(iterator first, iterator last);
bool empty() const;
: The class/parameter names in the prototype may not match the
version in the header file. Some have been modified to improve readability.
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Description
The first member function replaces the sequence controlled by
*this with the sequence [first, last). The second member function replaces the
sequence controlled by *this with a repetition of n elements of value x.
The third member function removes the element of the controlled
sequence pointed to by it. The fourth member function removes the elements of
the controlled sequence in the range [first, last). Both return an iterator
that designates the first element remaining beyond any elements removed, or
end() if no such element exists.
The last member function returns
true for an empty controlled sequence.
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Sample Code
//////////////////////////////////////////////////////////////////////
//
// Compile options needed: -GX
//
// assign.cpp : Shows the various ways to assign and erase elements
// from a list<T>.
//
// Functions:
//
// list::assign
// list::empty
// list::erase
//
// Written by Andrew Bradnan
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
//////////////////////////////////////////////////////////////////////
#include <list>
#include <iostream>
#if _MSC_VER > 1020 // if VC++ version is > 4.2
using namespace std; // std c++ libs implemented in std
#endif
typedef list<int, allocator<int> > LISTINT;
void main()
{
LISTINT listOne;
LISTINT listAnother;
LISTINT::iterator i;
// Add some data
listOne.push_front (2);
listOne.push_front (1);
listOne.push_back (3);
listAnother.push_front(4);
listAnother.assign(listOne.begin(), listOne.end());
// 1 2 3
for (i = listAnother.begin(); i != listAnother.end(); ++i)
cout << *i << " ";
cout << endl;
listAnother.assign(4, 1);
// 1 1 1 1
for (i = listAnother.begin(); i != listAnother.end(); ++i)
cout << *i << " ";
cout << endl;
listAnother.erase(listAnother.begin());
// 1 1 1
for (i = listAnother.begin(); i != listAnother.end(); ++i)
cout << *i << " ";
cout << endl;
listAnother.erase(listAnother.begin(), listAnother.end());
if (listAnother.empty())
cout << "All gone\n";
}
Program Output is:
1 2 3
1 1 1 1
1 1 1
All gone
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For the same information about list::assign, list::empty,
and list::erase, visit the following MSDN Web site:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcstdlib/html/vcsampsamplelistccassignstlsample.asp (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcstdlib/html/vcsampsamplelistccassignstlsample.asp)Back to the top
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