Yes, constraints can have helpful error messages!

[vit]

On Saturday, 9 April 2022 at 01:03:32 UTC, Marvin Hannott wrote:
> I was a bit surprised, reading the discussions about how 
> constraints aren't very helpful when it comes to figuring out 
> what is wrong. And I was even more surprised that of all things 
> `pragma` was called to the rescue. But isn't there a much 
> better, simpler way?
>
> [...]

There is another big problem with your solution:
```d
template isInt(T){
	static assert(is(T == int), "T is not int" );

	enum isInt = is(T == int);
}

void test(T)(T val)
if(isInt!T){

}

void test(double val){

}

void main() {

     test(int.init);
     test(double.init);
}

```

Function overloading doesn't work .