26 Numerics library [numerics]

26.6 Random number generation [rand]

26.6.2 Requirements [rand.req]

26.6.2.1 General requirements [rand.req.genl]

Throughout this subclause [rand], the effect of instantiating a template:
  • that has a template type parameter named Sseq is undefined unless the corresponding template argument is cv-unqualified and satisfies the requirements of seed sequence.
  • that has a template type parameter named URBG is undefined unless the corresponding template argument is cv-unqualified and satisfies the requirements of uniform random bit generator.
  • that has a template type parameter named Engine is undefined unless the corresponding template argument is cv-unqualified and satisfies the requirements of random number engine.
  • that has a template type parameter named RealType is undefined unless the corresponding template argument is cv-unqualified and is one of float, double, or long double.
  • that has a template type parameter named IntType is undefined unless the corresponding template argument is cv-unqualified and is one of short, int, long, long long, unsigned short, unsigned int, unsigned long, or unsigned long long.
  • that has a template type parameter named UIntType is undefined unless the corresponding template argument is cv-unqualified and is one of unsigned short, unsigned int, unsigned long, or unsigned long long.
Throughout this subclause [rand], phrases of the form “x is an iterator of a specific kind” shall be interpreted as equivalent to the more formal requirement that “x is a value of a type satisfying the requirements of the specified iterator type”.
Throughout this subclause [rand], any constructor that can be called with a single argument and that satisfies a requirement specified in this subclause shall be declared explicit.