const debacle

[Walter Bright]

Steven Schveighoffer wrote:
> So your answer essentially is, there is no way to specify that the function 
> will not modify the parameter but returns the same type passed in?

Right.

> Which means there is no check by the compiler to guarantee that source is 
> not modified (unless T is const), and basically, the coder has to rely on 
> the documentation to determine whether source will remain intact?  I think 
> this degrades the benefits of const in this context.

There's been some discussion about this, but no good resolution. (C++ 
has the same issue, btw.)