Example

STL defines a container template class called vector. It also provides an algorithm called find which takes in three arguments - two input iterators first and last indicating a range, and a value argument val - and returns an iterator pointing to the first position in the range in which the element matches the value val. The following code builds a vector of integer elements, finds the position of the first zero element in the vector, and then the position of the next zero element in the vector.

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		// create a vector with 10 elements

		vector<int> v(10);

		// add elements to the vector

		v.push_back(1);

		v.push_back(5);

		

		 // point to the first element of the vector

		vector::iterator i1 = v.begin();

		 // the following assertion will be true

		 assert(*i1 == 1 && *(i1+1) == 5);

		 // point past the last element of the vector

		vector::iterator i2 = v.end();

		 // find the first zero occurrence

		vector::iterator first = find(i1, i2, 0);

		if(first == i2)

				cout << ``vector has no zeroes'' << endl;

		else {

		 // find the second zero occurrence

				vector::iterator second = find(first, i2, 0);

				if (second == i2)

						cout << ``vector has one zero'' << endl;

				else

						cout << ``vector has two or more zeroes''

								 << endl;

		}