Re: [boost] Review Request: Creasing (Sequence Properties)

Subject: Re: [boost] Review Request: Creasing (Sequence Properties)
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2010-01-25 09:18:40

Grant Erickson wrote:
>
> The creasing algorithm templates define four template functions for
> determining the order properties of sequences, specifically:
>
>     * Increasing
>     * Decreasing
>     * Strictly Increasing
>     * Strictly Decreasing
>
> The implementation is a fairly trivial composition of the STL
> adjacent_find,
> not2 and {greater,less,greater_equal,less_equal}.

What about types that only support operator <?  They are pretty common and operator >, operator >=, and operator <= can be implemented in terms of operator <, right?  (Obviously, detecting whether the other operators are defined and using them is better.  Using a provided operator <= likely would be more efficient than synthesizing it from operator <.  The others are less likely to differ in efficiency.)

You could simply require all four operators, given the existence of Boost.Operators, but it would be easy enough to support a wider range of types with this library.

_____
Rob Stewart                           robert.stewart_at_[hidden]
Software Engineer, Core Software      using std::disclaimer;
Susquehanna International Group, LLP  http://www.sig.com

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