function t = test_is_int()
    % See: http://stackoverflow.com/a/6916862/97160
    
    % create a vector of doubles, containing integers and non-integers
    x = (1:1e5)';
    idx = ( rand(size(x)) < 0.5 );
    x(idx) = x(idx) + rand(sum(idx(:)),1);
    
    % create functions to test
    funcs = {@func1; @func2; @func3; @func4};
    
    % timeit and store results
    t = zeros(size(funcs));
    v = cell(size(funcs));
    for i=1:numel(funcs)
        f = @() funcs{i}(x);
        t(i) = timeit(f);
        v{i} = feval(f);
    end
    assert( isequal(v{:}) )
end

function v = func1(x)
    v = ~mod(x,1);
end

function v = func2(x)
    v = x==double(uint64(x));
end

function v = func3(x)
    v = x==floor(x);
end

function v = func4(x)
    v = x==round(x);
end