Add support implicit conversion between types

[Flamaros]

On Friday, 6 September 2013 at 10:33:07 UTC, ilya-stromberg wrote:
> Do you have any plans to support implicit conversion between 
> types?
>
> I have some code like this:
>
> struct Foo
> {
> 	this(int i)
> 	{
> 		//do something useful
> 	}
> }
>
> void bar(Foo f)
> {
> 	//do something else
> }
>
> void main()
> {
> 	Foo f = 5;//works
> 	
> 	bar(f);//works
> 	
> 	bar(Foo(5));//works

I think that the good way, to do 	

> 	bar(5);//Error: function app.bar (Foo f) is not callable using
> argument types (int)
> }
>
> So, D can't use constructor to convert "int" to "Foo" 
> implicitly.
> Can we add "implicit" keyword to allow do this:
>
> struct Foo
> {
> 	implicit this(int i)
> 	{
> 		//do something useful
> 	}
> }
>
> C++ allows this, but have "explicit" keyword.
> C# doesn't allow this, but have operator overloading for both 
> implicit and explicit cases.


It's difficult to never forget the "explicit" keyword in c++, and 
this little mistake can make you loose a lot of time.

I prefer to only have explicit conversions with cast or 
constructors calls, that all make the code easier to understand.