increment a single element of matrix/vector

[Patrick Alken]

I was thinking of adding two routines to GSL, to increment a single 
element of a matrix or vector by some amount, since I'm always doing 
things like:

gsl_vector_set(v, i, gsl_vector_get(v, i) + x);
which I think is ugly and annoying. Something like:

gsl_vector_add_element(v, i, x);
or
gsl_matrix_add_element(m, i, j, x);

would be really nice. Does anyone have any better suggestions for the 
function name? Or also is there another solution to this problem that I 
don't know about?

Patrick