Templates array detection

[ixid]

On Wednesday, 12 December 2012 at 12:34:34 UTC, bearophile wrote:
> Cube:
>
>> I'm having a problem getting templates to work correctly.
>> I want to handle arrays differently, but when I try to compile 
>> the following example code it says it matches more than 1 
>> template. What is the correct way to do this?
>>
>>
>> --
>> void main()
>> {
>>    foo(1);
>>    foo([1,1]);
>> }
>>
>> void foo(T)(T t)
>> {
>>    writeln(t);
>> }
>>
>> void foo(T)(T[] t)
>> {
>>    for(int i = 0; i < t.length; i++)
>>        writeln(t[i]);
>> }
>> --
>
> In general D templates refuse ambiguity. So to fix your 
> situation you have to state that the T in your first foo 
> overload is not an array:
>
> import std.stdio, std.traits;
>
> void main()
> {
>     foo(1);
>     foo([1, 1]);
> }
>
> void foo(T)(T t) if (!isArray!T)
> {
>     writeln(t);
> }
>
> void foo(T)(T[] t)
> {
>     foreach (ti; t)
>         writeln(ti);
> }
>
>
> Bye,
> bearophile

It's a pity it doesn't see T[] as the best fit and go with it on 
that basis.