C++ Truths

Programs need data. That's a no brainer. Programs are only as good as the data you provide them. Based on what kind of data is consumed, programs can be divided into two broad categories: (1) those that operate on regular data (a file), and (2) those that operate on other programs. The first kind of programs are abundant. Your browser, for instance, is showing you this page--its data. The second kind of programs are more interesting and they are called meta-programs. Meta-programs need data too. As with the other programs, meta-programs are only as good as the data you provide them. So what do we feed them? ... Well, In C++, more important than 'what' is 'when'. (remember Morpheus?) A C++ program is just a sequence of bits the compiler is trying to understand. So, while the compiler is trying to make sense of your program, most of it gets translated (to assembly) but some of it gets executed. Quite intriguing! We're talking about compile-time meta-programming...

It's common knowledge that Functional Programming is spreading like a wildfire in mainstream languages. Latest promoted languages: Java 8 and C++, both of which now support lambdas. So, let the lambdas begin! and may the fun be ever on your side. The same text is available in slides form on Slideshare . This blog post and the talk/slides are inspired by JSON inventor  Douglas Crockford . Write an Identity function that takes an argument and returns the same argument . auto Identity = [](auto x) { return x; }; Identity(3); // 3 Write 3 functions add, sub, and mul that take 2 parameters each and return their sum, difference, and product respectively. auto add = [](auto x, auto y) { return x + y; }; auto sub = [](auto x, auto y) { return x - y; }; int mul (int x, int y) { return x * y; }; Write a function, identityf, that takes an argument and returns an inner class object that returns that argument . auto identityf = [](auto x) { class Inner { int x; publi...

I am presenting at the SF Bay Area Association of C/C++ Users (ACCU)  meetup  on Wed, Mar 12th. Topic: Fun with Lambdas: C++14 Style. Slides and the blog will be available here so stay tuned.