Re: [boost] [review][mp11] Formal review of Mp11

Andrey Semashev wrote:

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The idea here is that mp_if_c can be used in two ways. One is mp_if_c, which gives either T or E depending on Cond. The other is mp_if_c, which is the same as std::enable_if_t - gives T when Cond, otherwise a substitution failure. ...

Why not separate the two use case into two primitives? We usually want one or the other and different tools would make sense, at least for documenting purpose.

One could go either way on that, I suppose. It makes sense because mp_if gives you T when C, otherwise E, and mp_if gives you T when C, otherwise <nothing>. "If C, T, otherwise, ..."