the.com/singleton
The design pattern that promised to solve everything and quietly became a global variable in a tuxedo.
means A thing existing as exactly one of its kind, whether a software object restricted to a single instance, a lone card, or a solo entity in a set.
from Coined in 1801 whist slang for a single card of a suit; borrowed into mathematics for one-element sets, then into 1990s software design where it earned its infamy.
Math senseA set holding exactly one element.
Programmer warningOften labeled an anti-pattern for hiding dependencies.
Birth useNamed for an only child too.