@printf does not accept * to specify field width

[eschnett]

I want to use this printf specification:

@sprintf "%0*d" len id

This should format the integer id using len digits, filled with 0 characters. The C printf supports the * specifier. Julia should offer an equivalent feature.

[quinnj]

I think this would be much easier to do now that #32859 is merged; it updates all the Printf code to use more modern dispatch patterns rather than relying on an insane amount of straight code generation.

[johanmon]

I added this:
#40105

[laborg]

This works now:

julia> @sprintf "%0*d" 5 42
"00042"