How can I merge multiple columns between two matrices?

I'm looking for a better way to merge two matrices based on a third. To take the first column one matrix and the second, third etc from the second based on custom mapping. For example:

a = 
    1   2   3   4
    1   2   3   4
    1   2   3   4
    1   2   3   4
    
b = 
    4   5   6   7
    4   5   6   7
    4   5   6   7
    4   5   6   7
    
c = 
    0   1   1   0

Using c to combine a and b I would want to get a final matrix d which looks like:

d = 
    1   5   6   4
    1   5   6   4
    1   5   6   4
    1   5   6   4

Currently I'm using a loop to select colums one at a time based on the c value, but this can get a little slow for larger matrices. Is there a simpler way to combine two matrices in this way?

Thanks

Answer 1

[madhan ravi]

In one line:

 d = (~c .* a) + (c .* b)

Answer 2

[Bruno Luong]

d = a
d(:,c==1) = b(:,c==1)

[Bruno Luong]

NOTE: This method works even if a or b contains -Inf/+Inf and NaN