Quick and easy way to turn transactional data into count of each item per unique receipt/invoice

Question

I am attempting to convert data of the form

receipts <- data.frame(receipt=c(193, 193, 193, 987, 215, 215), 
           product=c("spanner", "saw", "widget", "glue", "widget", "hammer"), 
           quantity=c(3,1,50,1,2,5), 
           stringsAsFactors = FALSE)

# i.e. 
#  receipt product quantity
#     193 spanner        3
#     193     saw        1
#     193  widget       50
#     987    glue        1
#     215  widget        2
#     215  hammer        5

Into data of the form

product_matrix <- data.frame(receipt=c(193,987,215), 
           spanner=c(3,0,0), 
           saw=c(1,0,0), 
           widget=c(50,0,2), 
           glue=c(0,1,0), 
           hammer=c(0,0,5), 
           stringsAsFactors = FALSE)
# i.e
# receipt spanner saw widget glue hammer
#     193       3   1     50    0      0
#     987       0   0      0    1      0
#     215       0   0      2    0      5

Is there a quick and easy way to do this? (I was working on a custom function, but it was taking a lot longer than I thought it would, and figured this is probably a reasonably common task for which a function may already exist)