Longer lines of code are faster.. eh?

I mean, I did have another programmer vehemently argue once long ago that putting more code on one line would make it “run faster.” But of course he was stark raving nuts. Trying to explain to him (with a straight face–which was challenging) how the interpreter or compiler would break that long line apart into discrete one-instruction-per-line statements–essentially identical to the result if he had gone ahead and just made the code readable instead of trying to out-clever the compiler–had no effect on him whatsoever. But I digress.

Craig Tullis on a StackOverflow answer.
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Premature optimization is the root of all evil.. NOT!

We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%.

Famous computer scientist Donald Knuth

His quote is often clipped down to just “premature optimization is the root of all evil”, but that is NOT TRUE.

Yes, don’t micro-benchmark everything when you begin a project, but please do think ahead. And once you’ve got the program working as intended, then make it faster by profiling and looking for the bottlenecks.

Choose the proper data structures. Array? List? Hashset? Queue? Dictionary? Caching?
Take a few moments and think it over.

How often will this line of code be ran? Do I need to inline it, or pull it out into a separate method?

Some useful C# Swap methods

public static class SwapExt
{
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static void Swap<T>(ref T? left, ref T? right) => (left, right) = (right, left);

	[Pure]
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static (T? right, T? left) Swap<T>(this T? left, T? right) => (right, left);

	[Pure]
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static (T? right, T? left) Swap<T>((T? left, T? right) tuple) => (tuple.right, tuple.left);
}

Pay close attention to which method you think is being used. (The refs versus the tuples.)