Re: 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.