A typeclass that provides the number of inhabitants of common types.

• libarary for Scala 3 (JS, JVM, and Native platforms)

"com.julianpeeters" %% "typesize" % "0.1.0"

Calling SizeOf[A].size returns an Int a Cardinality of three flavors:

• Finite: backed by a BigInt
• NonFinite: for types like List[A]
• TooBigToCompute: for types like String

Built-in typeclass instance are provided for common primitive and complex types, calculated by the following operations:

• +: take the sum of the members of a sealed trait
• *: take the product of the members of a tuple
• pow: take the exponentiation of the members of a function

import typesize.{Cardinality, SizeOf, given}

val c: Cardinality = summon[SizeOf[Option[Boolean]]].size
// c: Cardinality = Finite(i = 3)