opCall

Part of OperatorOverloadingCategory

Description

Shows how an opCall can be assigned to allow using C++-style "new"-ing on a class.

Example

import std.stdio : writefln;
import std.string;

class A
{
    this(uint x)
    {
        num = x;
    }

    char[] toString() 
    {
        return std.string.toString(num);
    }

    private uint num;

    
    static A opCall(uint x)
    {
        /* This overload allow the shorter C++ syntax for 
           "new"-ing the class. */

        return new A(x);
    }
}

void main()
{
    /* and you can create class objects the in a c++ syntax */
    A a = A(500);     
    A a2 = new A(567);

    writefln("Number: %s", a);
    writefln("Number: %s", a2);
}

Sample Batch File

@echo off
set pgm=OpCallExample
dmd %pgm%.d
%pgm%.exe
pause
erase %pgm%.obj
erase %pgm%.map

Expected Output

Number: 500
Number: 567

Tested Compiler and Operating System

• Tested with DMD 0.173.
• Compiled and tested on Windows 2000.

Source

Based on digitalmars.D:1539.