A template type is a special type that can take on different types when the type is initialized.

std::vector uses a template type

std::vector

Standard library class that provides the functionality of a dynamically growing array with a templated type.

• Defined in: include <vector>
• Initilalization: std::vector<T> v;
  • T is type. (See, it’s char or int or uiuc::Cube above)
• Add to (back) of array: ::push_back(T);
  • v.push_back(4)
• Access specific element: ::operator[] (unsigned pos);
  • v[0] : access to the first element in the vector
• Number of elements: ::size()
  • v.size

Template Type

When initilizing a templated type, the template type goes inside of <> at the end of the type name

std::vector<char> v1;

C++ allows for us to use the power of templates in building our own classes.

template <typename **T**>
class List{
	...
	private:
	**T** data_;
};

template <typename T>
int max(T a, T b) {
	if (a > b) { return a; }
	return b;
}

Templated variables are checked at compile time, which allows for errors to be caught before running the program.

The code above can accept int, string, whatever if comparision could work.

Dynamic size of array is not possible.