The British equivalent of "X objects in a trenchcoat"

Question

Today while giving a technical presentation to our research group, I used the expression

3 [Insert technical thing here]s in a trenchcoat.

Our advisor (British/African roots, but has been in the US for decades) hadn't heard this phrase before, so I was wondering:

1. Whether the expression is an Americanism
2. Whether there are equivalent expressions used by English speakers elsewhere.

Additional Context

Ion and Chris H. below are on the nose about the specific context -- in software systems it's not uncommon to implement one thing as a conglomeration of several other simpler things.

For example, if you have an interface IFace, which needs to expose fn1(), it may be most convenient to implement a complex object (the Trenchcoat) by wrapping together several smaller ones.

class Trenchcoat implements IFace {
  thing1: IFace
  thing2: IFace

  def fn1() {
     // a little preprocessing beforehand
     this.thing1.fn1();
     this.thing2.fn1();
     // a little makeup afterwards
  }
}

Answer 1

It is interesting that trench coat is of British origin:

The trench coat was developed as an alternative to the heavy serge greatcoats worn by British and French soldiers in the First World War. Invention of the trench coat is claimed by two British luxury clothing manufacturers, Burberry and Aquascutum, with Aquascutum's claim dating back to the 1850s. Thomas Burberry had invented gabardine fabric in 1879 and submitted a design for a British Army officer's raincoat to the War Office in 1901. (Wikipedia)

However, it is most probably in the US that the expression 2 kids in a trenchcoat (a first variant of x things in a trenchcoat) started [I have only encountered this phrase with animate nouns though]:

Two Kids In a Trenchcoat refers to a pop culture cliché in which two or more children attempt to fool others into believing they're one adult by having one child sit on another's shoulders, then cover themselves in an oversized coat. In the trope, this is usually done in order to gain access to adult-only material, such as tickets to an R-rated movie or alcohol. It has been seen in numerous forms of media and recreated in real life.

Origin
One of the earliest and most famous examples of this came in Disney's Snow White and the Seven Dwarfs (1937), in which the dwarf Dopey gets on top of Sneezy in order to dance with Snow White at her height (see video). (KnowYourMeme)

Since then this meme has been extended to (2 or 3) children/kids, or animals, or some kind of creatures in a trenchcoat to mean disguise, that which one is (hiding) underneath a façade. For example, the expression a pile of rats in a trenchcoat appeared with the movie Heartbreak High, in which a character says about herself:

I know I haven't been the best person recently. I've been a pile of rats in a trench coat really.

People have used on social media (especially Tiktok and Twitter) racoons, kobolds; some refer to it as the Totem Pole Trench. There is even a game Three Pigeons in a Trenchcoat. So it is not surprising that your advisor was not aware of this expression, since not everybody follows closely social media or pop/internet culture. You will not find this expression in dictionaries and it will be considered informal (Google Ngrams finds no instance of these variants in written texts).

But in order to find an equivalent, you will need to give more information about the exact meaning you want to use in a particular sentence. I am only guessing here, but at this point I would suggest:

3 [objects] disguised/camouflaged (as/in)

Camouflaged is a term of military origin so it may work better as an equivalent to the trench coat used in the war.

Answer 2

As a late millennial Brit, I'm familiar with this phrase, but it wouldn't surprise me if other (especially older or less online) Brits weren't familiar with it.

I'm not aware of any close equivalent that might be more familiar to those people and works in all the same contexts though, so any alternative would depend on the specific context.

Answer 3

Like other commentors with a British background, I'm familiar with the trope from TV shows (mainly cartoons), but not with its use in everyday conversation so I didn't connect the phrase to the visual image until I'd read some comments that joined the dots for me.

If you wanted to focus on the "low-quality / makeshift" aspect of the trope (since it's unlikely it would actually work in the real world) you could say:

cobbled together

cobble something together

to produce something quickly and without great care or effort, so that it can be used but is not perfect

The essay was cobbled together from some old notes.

The reforms have been very hastily cobbled together.

e.g. "X objects cobbled together"

or

bodged together

bodge something (up/together) to make or repair something in a way that is not as good as it should be

The fence was bodged together from old planks and doors.

Aside: a "bodger" was also a medieval craftsman who made furniture on-site in woodland where trees were cut down, so the quality was variable :-).

e.g. "X objects bodged together"

I might be showing my age a bit though with both of these - I'm not sure generations younger than mine would get either reference :-).