vrassert.m

Video IO toolbox for matlab. 用directshow做的

function vrassert(varargin)
%vrassert(testCondition)
%   Evaluates the test condition in the caller's context.  If the result is
%   false, an error is thrown indicating that the test failed.
%   TESTCONDITION should be a string (Matlab 2007a has a real ASSERT operator,
%   but many people don't have that version, so that's why we have this
%   function).
%
%EXAMPLES:
%   vrassert('1==2')      ==> assertion error generated
%   x=1; vrassert('x==1') ==> no error
%   vrassert(1==2)        ==> bad parameter error generated
%   vrassert('{a==3')     ==> error generated by Matlab (bad vrassert code)
%
%by Gerald Dalley

for i=1:nargin
  if (~ischar(varargin{i}))
    error('Type HELP ASSERT for usage');
  end
end

testCondition = join(' ', varargin);
if (~evalin('caller', testCondition))
  error(['ASSERT FAILED: ' testCondition]);
end


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function s = join(d,varargin)
% This JOIN function is an inlined version of Gerald Dalley's one posted at the
% Matlab Central website.  It is placed here as a convenience to users that
% have not downloaded it.

if (isempty(varargin)),
  s = '';
else
  if (iscell(varargin{1}))
    s = join(d, varargin{1}{:});
  else
    s = varargin{1};
  end

  for ss = 2:length(varargin)
    s = [s d join(d, varargin{ss})]; %#ok<AGROW>
  end
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function test %#ok<DEFNU>
% Copy-and-paste the below code into the command window to test this
% function.

clear all;

worked = 0; try vrassert('1==2'); catch worked = 1; end
if (~worked), error('Test failed'); end

worked = 1; try x=1; vrassert('x==1'); catch worked = 0; end
if (~worked), error('Test failed'); end

worked = 0; try vrassert(1==2); catch worked = 1; end
if (~worked), error('Test failed'); end

worked = 0; try vrassert('{a==3'); catch worked = 1; end
if (~worked), error('Test failed'); end