[ Stephan Tolksdorf adds pre-Bellevue: ]

In [rand.dist.samp.pconst]:

Proposed wording a)

Change in para. 2

Constructs a piecewise_constant_distribution object with n = 1, p₀ = w₀ = 1, b₀ = 0, and b₁ = 1

and change in para. 5

A vector<result_type> whose size member returns n and whose operator[] member returns p_k the weight w_k as a double value when invoked with argument k for k = 0, ..., n-1

Proposed wording b)

Change both occurrences of

"piecewise_constant_distribution(InputIteratorB firstB, InputIteratorB lastB,
                                 InputIteratorW firstW, InputIteratorW lastW)

and change in para. 3

the length of the sequence w starting from firstW shall be at least n, *firstW shall return a value w₀ that is convertible to double, and any w_k for k >= n shall be ignored by the distribution [firstW, lastW) shall form a sequence w of length n whose leading element w₀ shall be convertible to double

Proposed resolution:

See N2424 for the proposed resolution.

[ Bellevue: ]

In N2424. There is already precedent elsewhere in the library. Follows existing convention. NAD.

[ Stephan Tolksdorf adds pre-Bellevue: ]

In reply to the discussion in N2424 I'd like to make the same comments as for 736.

1. The discussion in point T11 above regarding probabilities() similarly applies to the method densities() of piecewise_constant_distribution.

2. The design of the constructor

   template <class InputIteratorB, class InputIteratorW> 
   piecewise_constant_distribution( InputIteratorB firstB, InputIteratorB lastB, 
                                    InputIteratorW firstW);
   

   is unnecessarily unsafe, as there is no separate end-iterator given for the weights. I can't see any performance or convenience reasons that would justify the risks inherent in such a function interface, in particular the risk that input error might go unnoticed.

Possible resolution: I propose to add an InputIteratorW lastW argument to the interface.