Explain function syntax

[user1234]

On Saturday, 20 September 2025 at 02:36:47 UTC, Steven 
Schveighoffer wrote:
> What is a function type? It's the internal type that the 
> compiler has for a function, which you actually cannot express 
> in syntax.

Actually D has a syntax to expression function types:

```d
alias FT = void(int);

void v(int a){}
static assert(is(typeof(v) == function));
static assert(is(typeof(v) == FT));
```