Re: type determination

[Ali Çehreli]

On 11/26/2012 09:03 PM, dsmith wrote:

How can I make something like the following work without "Error: cannot
append type double to type string[]" ?


T[] some_function(T[] var) {
T[] var2;
double a = 12.34;
string b = "hello";

if(typeof(var).stringof == "double") {
var2 ~= a;
}
if(typeof(var).stringof == "string") {
var2 ~= b;
}

...
}

One way is to dispatch the selection to a "traits" template:

template valueToAdd(T : double)
{
    T valueToAdd = 12.34;
}

template valueToAdd(T : string)
{
    T valueToAdd = "hello";
}


T[] some_function(T)(T[] var) {
    T[] var2;
    var2 ~= valueToAdd!T;
    return var2;
}

import std.stdio;

void main()
{
    writeln(some_function([ 1.25, 2.75 ]));
    writeln(some_function([ "abc", "xyz" ]));
}

Ali