// SPDX-License-Identifier: Apache-2.0

package chisel3.util

import chisel3._

/** Concatenates elements of the input, in order, together.
  *
  * @example {{{
  * Cat("b101".U, "b11".U)  // equivalent to "b101 11".U
  * Cat(myUIntWire0, myUIntWire1)
  *
  * Cat(Seq("b101".U, "b11".U))  // equivalent to "b101 11".U
  * Cat(mySeqOfBits)
  * }}}
  */
object Cat {
  /** Concatenates the argument data elements, in argument order, together. The first argument
    * forms the most significant bits, while the last argument forms the least significant bits.
    */
  def apply[T <: Bits](a: T, r: T*): UInt = apply(a :: r.toList)

  /** Concatenates the data elements of the input sequence, in reverse sequence order, together.
    * The first element of the sequence forms the most significant bits, while the last element
    * in the sequence forms the least significant bits.
    *
    * Equivalent to r(0) ## r(1) ## ... ## r(n-1).
    * @note This returns a `0.U` if applied to a zero-element `Vec`.
    */
  def apply[T <: Bits](r: Seq[T]): UInt = SeqUtils.asUInt(r.reverse)
}
