Rationale:

Berlin: N1932 makes this moot: variate_generator has been eliminated.

[ Mont Tremblant: Jens reccommends NAD, min/max not needed everywhere. Marc supports having min and max to satisfy generic programming interface. ]

Proposed resolution:

Consequence 1: Remove the precondition clauses [tr.rand.var]/16 and /18.

Consequence 2: Add max() and min() functions to those distributions that do not already have them.

Paragraph 3 requires that template argument U (which corresponds to template parameter Engine) satisfy all uniform random number generator requirements. However, there is no analogous requirement regarding the template argument that corresponds to template parameter Distribution. We believe there should be, and that it should require that this template argument satisfy all random distribution requirements.