You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: vl_compile.m
    path of file: ./repos/2016_person_re-ID/vlfeat/toolbox
    
    the code of the file until where you have to start completion: function vl_compile(compiler)
% VL_COMPILE  Compile VLFeat MEX files
%   VL_COMPILE() uses MEX() to compile VLFeat MEX files. This command
%   works only under Windows and is used to re-build problematic
%   binaries. The preferred method of compiling VLFeat on both UNIX
%   and Windows is through the provided Makefiles.
%
%   VL_COMPILE() only compiles the MEX files and assumes that the
%   VLFeat DLL (i.e. the file VLFEATROOT/bin/win{32,64}/vl.dll) has
%   already been built. This file is built by the Makefiles.
%
%   By default VL_COMPILE() assumes that Visual C++ is the active
%   MATLAB compiler. VL_COMPILE('lcc') assumes that the active
%   compiler is LCC instead (see MEX -SETUP). Unfortunately LCC does
%   not seem to be able to compile the latest versions of VLFeat due
%   to bugs in the support of 64-bit integers. Therefore it is
%   recommended to use Visual C++ instead.
%
%   See also: VL_NOPREFIX(), VL_HELP().

% Authors: Andrea Vedadli, Jonghyun Choi

% Copyright (C) 2007-12 Andrea Vedaldi and Brian Fulkerson.
% All rights reserved.
%

    
function vl_compile(compiler)
% VL_COMPILE  Compile VLFeat MEX files
%   VL_COMPILE() uses MEX() to compile VLFeat MEX files. This command
%   works only under Windows and is used to re-build problematic
%   binaries. The preferred method of compiling VLFeat on both UNIX
%   and Windows is through the provided Makefiles.
%
%   VL_COMPILE() only compiles the MEX files and assumes that the
%   VLFeat DLL (i.e. the file VLFEATROOT/bin/win{32,64}/vl.dll) has
%   already been built. This file is built by the Makefiles.
%
%   By default VL_COMPILE() assumes that Visual C++ is the active
%   MATLAB compiler. VL_COMPILE('lcc') assumes that the active
%   compiler is LCC instead (see MEX -SETUP). Unfortunately LCC does
%   not seem to be able to compile the latest versions of VLFeat due
%   to bugs in the support of 64-bit integers. Therefore it is
%   recommended to use Visual C++ instead.
%
%   See also: VL_NOPREFIX(), VL_HELP().

% Authors: Andrea Vedadli, Jonghyun Choi

% Copyright (C) 2007-12 Andrea Vedaldi and Brian Fulkerson.
% All rights reserved.
%
% This file is part of the VLFeat library and is made available under
% the terms of the BSD license (see the COPYING file).

if nargin < 1, compiler = 'visualc' ; end
switch lower(compiler)
  case 'visualc'
    fprintf('%s: assuming that Visual C++ is the active compiler\n', mfilename) ;
    useLcc = false ;
  case 'lcc'
    fprintf('%s: assuming that LCC is the active compiler\n', mfilename) ;
    warning('LCC may fail to compile VLFeat. See help vl_compile.') ;
    useLcc = true ;
  otherwise
    error('Unknown compiler ''%s''.', compiler)
end

vlDir = vl_root ;
toolboxDir = fullfile(vlDir, 'toolbox') ;

switch computer
  case 'PCWIN'
    fprintf('%s: compiling for PCWIN (32 bit)\n', mfilename);
    mexwDir = fullfile(toolboxDir, 'mex', 'mexw32') ;
    binwDir = fullfile(vlDir, 'bin', 'win32') ;
  case 'PCWIN64'
    fprintf('%s: compiling for PCWIN64 (64 bit)\n', mfilename);
    mexwDir = fullfile(toolboxDir, 'mex', 'mexw64') ;
    binwDir = fullfile(vlDir, 'bin', 'win64') ;
  otherwise
    error('The architecture is neither PCWIN nor PCWIN64. See help vl_compile.') ;
end