<ply-base.h>

namespace ply

Random Numbers

The Random class generates pseudorandom integers and floating-point values.

This class uses the well-known xoroshiro128** algorithm by Sebastiano Vigna and David Blackman internally. To use it, construct a Random object (optionally passing an explicit seed), then call any of its member functions as many times as needed.

This class isn't thread-safe. Its member functions must not be called concurrently from separate threads.

Random()

Constructs a pseudorandom number generator seeded from the system clock.

Random(u64 seed)

Constructs a pseudorandom number generator using an explicit seed. The same seed always generates the same sequence of pseudorandom numbers.

u32 generate_u32()

Returns an unsigned integer uniformly distibuted over the entire range of representable 32-bit values. Use the modulo % operator to restrict the value to a smaller range.

u64 generate_u64()

Returns an unsigned integer uniformly distibuted over the entire range of representable 64-bit values. Use the modulo % operator to restrict the value to a smaller range.

double generate_double()

Returns a uniformly-distributed floating-point number that is greater than or equal to 0.0 and less than 1.0.

// Generate some 4-digit random numbers
Random r;
Stream out = get_stdout();
for (u32 i = 0; i < 5; i++) {
    out.format("{}\n", r.generate_u32() % 9000 + 1000);
}

2910
7364
5994
8732
1678