D LanguageTemplates

Syntax

  • template identifier (TemplateParameterList) { ... }
  • struct identifier (TemplateParameterList) { ... }
  • class identifier (TemplateParameterList) { ... }
  • ReturnType identifier (TemplateParameterList)(ParameterList) { ... }
  • identifier!(TemplateInvocationList)

Function with one template

import std.stdio;

T min(T)(in T arg1, in T arg2) {
    return arg1 < arg2 ? arg1 : arg2;
}

void main() {
    //Automatic type inference
    writeln(min(1, 2));
    
    //Explicit type
    writeln(min!(ubyte)(1, 2));
    
    //With single type, the parenthesis might be ommited
    writeln(min!ubyte(1, 2));
}

template

An template can be introduced with template. It can contain functions and classes and other constructs.

template StaticArray(Type, size_t Length) {
     class StaticArray {
          Type content[Length];
          
          size_t myLength() {
            return getLength(this);
          }
     }
     
     private size_t getLength(StaticArray arr) {
          return Length;
     }
}

void main() {
    StaticArray!(int, 5) arr5 = new StaticArray!(int, 5);
    import std.stdio;
    writeln(arr5.myLength());
}