The engines produce
unsigned numbers, and each number in the engine’s range has the same likelihood of being generated. Applications often need numbers of different types or distributions. The library handles both these needs by defining different distributions that, when used with an engine, produce the desired results. Table 17.16 (overleaf) lists the operations supported by the distribution types.
Programs often need a source of random floating-point values. In particular, programs frequently need random numbers between zero and one.