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digitalmars.D.learn - Method-call based on template argument

reply nrgyzer <nrgyzer gmail.com> writes:
I'm trying to do the following:

module myModule;

int calculate(T)(int a, int b) if(T == "add") {
   return a + b;
}

int calculate(T)(int a, int b) if(T == "subtract) {
   return a - b;
}

But when I try to run the following code, I get "template myModule.calculate"
does not match any function template declaration":

void main() {

   int a = 10;
   int b = 20;
   std.stdio.writeln(calculate!("add")(a, b));
   std.stdio.writeln(calculate!("subtract")(a, b));

}

Is there any way to check if the given template argument is "add" or
"subtract"? I also tried:

int calculate(string T)(int a, int b) if(T == "add") {
   return a + b;
}

int calculate(string T)(int a, int b) if(T == "subtract) {
   return a - b;
}

... without any success (I'll get an instantiation error).
May 09 2012
parent reply sclytrack <sclytrack iq87.fr> writes:
On 05/09/2012 12:33 PM, nrgyzer wrote:
 void main() {

     int a = 10;
     int b = 20;
     std.stdio.writeln(calculate!("add")(a, b));
     std.stdio.writeln(calculate!("subtract")(a, b));

 }

Below works ----------- import std.stdio; int calculate(string T)(int a, int b) if(T == "add") { return a + b; } int calculate(string T)(int a, int b) if(T == "subtract") { return a - b; } void main() { int a = 10; int b = 20; std.stdio.writeln(calculate!("add")(a, b)); std.stdio.writeln(calculate!("subtract")(a, b)); } Output ------ 30 -10
May 09 2012
parent nrgyzer <nrgyzer gmail.com> writes:
Hm... yes - works. I simply rewrote my method-header and it just works, too...
but thanks :)
May 09 2012