c++c++11

(C++) What does it mean when a data type is between a '<' and '>' sign?

I'm reading Bjarne Stroustrup's book on C++ and he uses things like vector<int> or complex<double>. What does it mean when a data type like int is between a < and > sign?

Tried Googling but it won't recognize my < or > enter image description here

enter image description here

Solution

  • They're templates.

    Function templates are special functions that can operate with generic types. This allows us to create a function template whose functionality can be adapted to more than one type or class without repeating the entire code for each type.

    for example:

    template <class C>
C add (C a, C b) {
  C result = a + b;
  return (result);
}

int a = 1;
int b = 2;

add<int>(a, b); //returns 3

float c = 1.5
float d = 0.5

add<float>(c, d) // returns 2.0