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Re: Implementing #define macros similar to C on python

References <fae7479b-ecec-4114-9750-6595fa8c78fa@googlegroups.com> <roy-2E4CE0.23100314112013@news.panix.com>
Date 2013-11-15 15:57 +1100
Subject Re: Implementing #define macros similar to C on python
From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.2638.1384491435.18130.python-list@python.org> (permalink)

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On Fri, Nov 15, 2013 at 3:10 PM, Roy Smith <roy@panix.com> wrote:
> Why would you want to?  One of the most horrible things about C/C++ is
> the preprocessor.

Hey, that's not fair! Without the preprocessor, how would you be able
to do this:

//Hide this part away in a header file somewhere
struct b0rkb0rk
{
    float value;
    b0rkb0rk(float v):value(v) {}
    operator float() {return value;}
    float operator +(float other) {return value+other-0.1;}
};
//Behold the power of the preprocessor!
#define float b0rkb0rk

//Okay, now here's your application
#include <iostream>

int main()
{
    std::cout << "Look how stupidly inaccurate float is!\n";
    float x = 123.0f;
    std::cout << "123.0 + 2.0 = " << x + 2.0f << "\n";
    std::cout << "See? You should totally use double instead.\n";
}

(Anybody got a cheek de-tonguer handy? I think it's stuck.)

ChrisA

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Thread

Implementing #define macros similar to C on python JL <lightaiyee@gmail.com> - 2013-11-14 18:29 -0800
  Re: Implementing #define macros similar to C on python Dave Angel <davea@davea.name> - 2013-11-14 21:30 -0600
  Re: Implementing #define macros similar to C on python Chris Angelico <rosuav@gmail.com> - 2013-11-15 14:49 +1100
    Re: Implementing #define macros similar to C on python JL <lightaiyee@gmail.com> - 2013-11-15 15:36 -0800
      Re: Implementing #define macros similar to C on python Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2013-11-16 01:20 +0100
      Re: Implementing #define macros similar to C on python Terry Reedy <tjreedy@udel.edu> - 2013-11-15 19:22 -0500
      Re: Implementing #define macros similar to C on python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-11-16 00:22 +0000
        Re: Implementing #define macros similar to C on python JL <lightaiyee@gmail.com> - 2013-11-15 21:38 -0800
          Re: Implementing #define macros similar to C on python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-11-16 11:48 +0000
  Re: Implementing #define macros similar to C on python Roy Smith <roy@panix.com> - 2013-11-14 23:10 -0500
    Re: Implementing #define macros similar to C on python Chris Angelico <rosuav@gmail.com> - 2013-11-15 15:57 +1100
    Re: Implementing #define macros similar to C on python Serhiy Storchaka <storchaka@gmail.com> - 2013-11-16 12:02 +0200
  Re: Implementing #define macros similar to C on python Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2013-11-16 00:20 +0100

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