A type that can be initialized with a floating-point literal.

The standard library floating-point types---Float, Double, and Float80 where available---all conform to the ExpressibleByFloatLiteral protocol. You can initialize a variable or constant of any of these types by assigning a floating-point literal.

// Type inferred as 'Double'
let threshold = 6.0

// An array of 'Double'
let measurements = [2.2, 4.1, 3.65, 4.2, 9.1]

Conforming to ExpressibleByFloatLiteral

To add ExpressibleByFloatLiteral conformance to your custom type, implement the required initializer.