Posting C++ Code

I decided that if I'm going to be posting code, I might as well figure out how to make it look like code. In a comment on my last post, Nuno Barreiro's suggested I use SyntaxHighlighter, so I decided to give it a try.

Never in the history of software development has there been a tool with more explicit no-brains-are-required installation and usage tutorials.  My favorite is this one, because, really, how much more can you ask than for screen shots with arrows pointing where to click and "Click this" directives?  I threw caution to the wind and did exactly as I was told. Security be damned, I wanted my code to be syntax-highlighted, and I was in a hurry!

It didn't work.  The syntax of my code was not highlighted, and I got an error telling me that the brush I needed couldn't be found. An hour or so of googling and trial and error and more googling and more trial and more error ensued before I figured out that the name of the brush I needed was "c++", not "C++". That despite the fact that the documented brush name is "C++" and the name of the JavaScript file is shBrushCpp.js.  (Alias brush names are "cpp" and "c", both of which also work, but by the time I started playing around with the aliases, I was beyond noticing that the file name contained "Cpp", but the alias is "cpp".  My bad.)

To get code to display properly, you have to enter it in HTML mode (at least in Blogger, which is the platform I'm using), and you have to remember to transform all opening angle brackets ("<") into their fetching HTML equivalents ("&lt;"). I use Centricle.com's Encode/Decode HTML Entities page for that.

To get C++ code highlighting in Blogger, then (and I'm posting this here more for me than in the hope it might be useful to somebody else) you first blindly point, click, copy, and configure as per this page (initial setup) and this page (additional configuration). For each code fragment you want to appear in your blog, you:

1. Write the code elsewhere, presumably where you can easily edit and test it. I use Emacs, but I've heard tell that there are other code and text editors.
2. Transform the code into HTML-friendly form via something like the Encode/Decode HTML Entities page.
3. Copy the transformed code into the HTML editor in Blogger.  Put said code into a pre block as follows:

<pre class="brush: c++">
Your code goes here
</pre>

In the words of technical support professionals everywhere, it works for me.

As a demonstration, here's some code I've been playing around with this evening.  The goal is to see which of several potential constructors is called when an object (an lvalue, if you insist on knowing) is copied. Try to predict what it will do before you feed it to your compiler. When I run it under gcc 4.7, I'm surprised by what I see.

#include <iostream>

class Widget {
public:
  Widget(){};

  Widget(const Widget&) { std::cout << "Widget copy ctor  "; }

  template<typename T>
  Widget(const T&) { std::cout << "Generalized Widget copy ctor  "; }

  template<typename T>
  Widget(T&&) { std::cout << "Universal Widget ctor  "; }
};


void endLine() { std::cout << '\n'; }


int main()
{
  Widget w;

  {
    std::cout << "Create Widget from Widget:\n";
    std::cout << "  Direct init w/parens: ";   Widget wcopy1(w);  endLine();
    std::cout << "  Copy init           : ";   Widget wcopy2 = w; endLine();
    std::cout << "  Direct init w/braces: ";   Widget wcopy3 {w}; endLine();
    endLine();
  }


  {
    std::cout << "Create auto from Widget:\n";
    std::cout << "  Direct init w/parens: ";   auto wcopy1(w);   endLine();
    std::cout << "  Copy init           : ";   auto wcopy2 = w;  endLine();
    std::cout << "  Direct init w/braces: ";   auto wcopy3 {w};  endLine();
    endLine();
  }

  const Widget cw;

  {
    std::cout << "Create Widget from const Widget:\n";
    std::cout << "  Direct init w/parens: ";   Widget wcopy1(cw);  endLine();
    std::cout << "  Copy init           : ";   Widget wcopy2 = cw; endLine();
    std::cout << "  Direct init w/braces: ";   Widget wcopy3 {cw}; endLine();
    endLine();
  }

  {
    std::cout << "Create auto from const Widget:\n";
    std::cout << "  Direct init w/parens: ";   auto wcopy1(cw);   endLine();
    std::cout << "  Copy init           : ";   auto wcopy2 = cw;  endLine();
    std::cout << "  Direct init w/braces: ";   auto wcopy3 {cw};  endLine();
    endLine();
  }
}

Update 10/17/12: Having run across this blog post, I also gave Google's Prettify a try. I don't like the result as well as that of SyntaxHighlighter, but judge for yourself.  Here's a prettified version of the Widget class above:

class Widget {
public:
  Widget(){};

  Widget(const Widget&) { std::cout << "Widget copy ctor  "; }

  template<typename T>
  Widget(const T&) { std::cout << "Generalized Widget copy ctor  "; }

  template<typename T>
  Widget(T&&) { std::cout << "Universal Widget ctor  "; }
};

Update 6/12/20: I removed support for SyntaxHighlighter and Google Prettify from the blog, because neither seems to be supported any longer. I did only cursory testing, but I'm hoping that the result will be that code examples in my blog posts continue to look like code, except they won't be syntax-highlighted.