What does the angle bracket syntax mean in a function call?

Question

What does this syntax mean?

ForExample<Something>();

Can someone explain with a few examples how and what for it can be used?

`ForExpample` would be a function, templated on type `Something` and is being called with no arguments. — Cory Kramer, Jul 20 '21 at 12:05
Please invest in [some good C++ books](https://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list). — Some programmer dude, Jul 20 '21 at 12:07
@CoryKramer It could also be a class-template, and this statement creates a temporary object. — Some programmer dude, Jul 20 '21 at 12:08
Without any kind of context (most specifically the definition or at least declaration of `ForExample`) it's impossible to say anything certain. — Some programmer dude, Jul 20 '21 at 12:10

score 2 · Accepted Answer · answered Jul 20 '21 at 12:17

2

This code could be a call of the template function or instantiation of temporary class object. For example, function is defined as:

template <typename T>
void ForExample(){
   // Do something
}

This function can be called as:

ForExample<int>();

In your case type Something can be any type (int, double, string, float ...)

Or we can define template class:

template <typename T>
class ForExample {
 // something
};

Temporary object can be created as:

ForExample<int>();

answered Jul 20 '21 at 12:17

Dzemo997

Why do I need to specify the data type in <> when calling the function? – ClownieAdd Jul 20 '21 at 18:52
1

As the name implies "template" is not the real function definition. Think about template like pattern which is used to create real function. You have to replace type T with real type (int, double, string...), type T is generic type and could be anything you want. And that's the reason you have to specify when calling function. This process is called instantiation. – Dzemo997 Jul 20 '21 at 19:10

1 Answers1