import Foundation

private let numberFormatter: NumberFormatter = {
  let formatter = NumberFormatter()
  formatter.numberStyle = .decimal
  formatter.maximumFractionDigits = 2
  return formatter
}()

extension String.StringInterpolation {
  mutating func appendInterpolation(double: Double) {
    appendInterpolation(numberFormatter.string(from: NSNumber(value: double))!)
  }
}