Preserving const? -- A potential solution

[Tim M]

>> If you're not actually responding to a post, please don't quote the
>> entire thing in your message.

The subject should have been more accurate then but yes preserving  
constness is very usefull though I prefer the inferred template way:

module tconst;

import std.stdio;

T max(T)(T a, T b)
{
       if(a > b)
             return a;
       else
             return b;
}

void main()
{
       invariant int a = 2;
       invariant int b = 4;
       auto c = max(a,b); //c becomes an invariant int
       c = 5; //should fail as c is also invariant
}