generic + numeric + literals = abomination

[so]

Well, i am having hard time explaining, it is not a surprise that you  
don't understand.
To make things clearer, lets forget floats for a seconds and change your  
code to standard unsigned types.


import std.stdio: writeln;

struct Vector(T) {
     this(T m) { mm = m; }
     Vector opBinary(string op:"*", T2)(T2 m) if(is(T2 == T)) {
         return Vector(mm * m);
     }
     T mm;
}

void test(T)() {
     Vector!T v = Vector!T(5);
     Vector!T u = v * 3;
     writeln("u: ", u.mm);
}

void main() {
     test!ubyte();
     test!ushort();
     test!uint();
     test!ulong();
}

All the tests fail as they should, but check it out, what is wrong with  
the templates above?
You can represent 3, and 5 with all these 4 types, but since 3, and 5  
actually is an "int" it fails.
Now think about it again with my proposal in mind. Where we add a generic  
literal, for this situation,
which covers entire unsigned types, lets pick a generic literal for them,  
say... "gu"

void test(T)() {
     Vector!T v = Vector!T(5gu);
     Vector!T u = v * 3gu;
     writeln("u: ", u.mm);
}

Thanks!

On Sun, 28 Mar 2010 12:29:17 +0400, bearophile <bearophileHUGS at lycos.com>  
wrote:

> I don't understand your problem/needs, sorry.
>
> Bye,
> bearophile


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