typedefs are useless

[Bill Baxter]

BCS wrote:
> Steven Schveighoffer wrote:
>> This may have arisen somewhere before, but...
>>
>> Let's say I want a way to create a type that's like a long, but is not 
>> implicitly convertable from a long.
> [...]
> 
> this is getting really close to something I have wanted for some time:
> 
> typedef real MyReal
> {
>    // stuff
> }
> 
> it would be like a struct that inherits from a primitive type. The this 
> would be of the base type and you wouldn't be allowed to add any 
> members. However this would allow you to do things like overload the 
> operators. The one things in particular I would like to do would be to 
> overload just the typing of the operators. This would result in the 
> implementation of + (for instance) being the same as + on the underlying 
> type, but the type of the result would be redefined. The point of this 
> would be to allow a program to restrict the type that could be used. A 
> concrete use case would be a SIUinits type that would, at compile time, 
> verify unit correctness, but in the end would result in exactly the same 
> code as if bare FP values were used.
> 
> Thoughts?

Why not just make that behavior triggered when you do

struct MyReal : real
{
...
}

?