Binary String from Number types

toBinary.swift

// toBinary
func toBinary<T: UnsignedIntegerType>(value: T) -> String {
    let str = String(value, radix:2)
    let size = sizeofValue(value) * 8
    let padd = String(count: (size - str.characters.count), repeatedValue: Character("0"))
    return padd + str
}
func toBinary<T: _SignedIntegerType>(value: T) -> String {
    let size = sizeofValue(value) * 8
    let signed: IntMax = value.toIntMax()
    let unsigned: UIntMax = UIntMax(bitPattern: signed)
    var str = String(unsigned, radix:2)
    switch str.characters.count {
    case let count where count > size:
        str = str[str.startIndex.advancedBy(count-size) ..< str.endIndex]
    default:
        let padd = String(count: (size - str.characters.count), repeatedValue: Character("0"))
        str = padd + str
    }
    return str
}
func toBinary<T: FloatingPointType>(value: T) -> String {
    let size = sizeofValue(value)
    if size == sizeof(UInt32) {
        let unsigned = unsafeBitCast(value, UInt32.self)
        let str = String(unsigned, radix:2)
        let padd = String(count: (size*8 - str.characters.count), repeatedValue: Character("0"))
        return padd + str
    } else if size == sizeof(UInt64) {
        let unsigned = unsafeBitCast(value, UInt64.self)
        let str = String(unsigned, radix:2)
        let padd = String(count: (size*8 - str.characters.count), repeatedValue: Character("0"))
        return padd + str
    }
    return ""
}
func toBinary(value: Bool) -> String {
    if sizeofValue(value) == sizeof(UInt8) {
        let unsigned = unsafeBitCast(value, UInt8.self)
        let str = String(unsigned, radix:2)
        let padd = String(count: (8 - str.characters.count), repeatedValue: Character("0"))
        return padd + str
    }
    return ""
}
func toBinary(value: Character) -> String {
    let size = sizeofValue(value)
    return ""
}

print(toBinary(UInt8(10)))  // 00001010
print(toBinary(UInt8(255))) // 11111111
print(toBinary(Int8(10)))   // 00001010
print(toBinary(Int8(-1)))   // 11111111
print(toBinary(Float(0.5))) // 00111111000000000000000000000000
print(toBinary(Float(-2.0))) // 11000000000000000000000000000000
print(toBinary(true))       // 00000001
print(toBinary(false))      // 00000000