July 21, 2026
Overloaded and under control
(Ab)Using Overload Sets to Create Ad-Hoc Template APIs in D
This obscure coding trick has developers intrigued, confused, and asking if it helps build websites
TLDR: The article shows how D programmers can use a clever naming trick to build flexible reusable code without a single formal master type. In the comments, veterans praised the hidden power while everyone else latched onto the funniest, most practical question: does any of this actually help ship a website?
A deep-dive into the D programming language somehow turned into a tiny comment-section soap opera, and honestly, that’s where the real entertainment is. The article explains a sneaky coding trick: instead of making one big master template, developers can bunch together several similarly named pieces and treat them like one flexible menu of options. In plain English, it’s a way to write reusable code without building a huge formal system first. For D fans, that’s catnip. For everyone else, it reads a bit like a magician explaining how the rabbit got in the hat.
The strongest reaction came from D creator Walter Bright, who basically gave the concept an air of old-school legitimacy, calling it one of those quiet features that has been doing heavy lifting for years. That’s the tech equivalent of a band member casually revealing the backup singer wrote half the hits. Then came the instantly relatable comment from Kapendev, who swerved the conversation from theory to survival mode: "Cool, but can this help me with web development? My senior told me to ask." And just like that, the mood shifted from abstract brain gymnastics to workplace comedy.
That contrast is the whole drama: one side is marveling at elegant language design, while the other is giving major "this is nice, but I still have deadlines" energy. The humor writes itself. The vibe is half academic flex, half junior-dev panic, with a sprinkle of meme-worthy confusion over whether this clever trick is revolutionary or just another way programmers entertain themselves instead of shipping features.
Key Points
- •The article explains that in D, an overload set is the set of same-named functions in the same scope that participate in overload resolution.
- •It shows that an overloaded function name such as `bar` can be passed as an alias template parameter and still resolve correctly by argument type.
- •The article demonstrates integer-value specialization to build an overload set that can be traversed like a compile-time lookup table.
- •It uses a `Length` template with `__traits(compiles)` to determine how many overload specializations are available.
- •A vector-interface example shows how specialized declarations like `GVec!(2, T)`, `GVec!(3, T)`, and `GVec!(4, T)` can form an ad-hoc template API without a primary template definition.