\subsection{InstructionDecoder Class}
\label{sec:instructionDecoder}

The \code{InstructionDecoder} class decodes instructions, given a buffer of bytes and a
length, and constructs an Instruction. 

\begin{apient}
  InstructionDecoder(const unsigned char *buffer, size_t size,
                     Architecture arch)
  InstructionDecoder(const void *buffer, size_t size,
                     Architecture arch)
\end{apient}

\apidesc{Construct an \code{InstructionDecoder} over the provided
\code{buffer} and \code{size}. We consider the buffer to contain
instructions from the provided \code{arch}, which must be from the set
\code{\{Arch\_x86, Arch\_x86\_64, Arch\_ppc32, Arch\_ppc64\}}. }

\begin{apient}
Instruction::Ptr decode();
\end{apient}

\apidesc{Decode the next address in the buffer provided at
construction time, returning either an instruction pointer or
\code{NULL} if the buffer contains no undecoded instructions.}