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Re: Defs.h minmax() change/fix [message #24069 is a reply to message #24061]

Thu, 24 December 2009 10:58

mirek
Messages: 14256
Registered: November 2005

Ultimate Member

kohait00 wrote on Wed, 23 December 2009 13:31

hi there

in Defs.h:214

why not using

template <class T>
inline const T& minmax(const T& x, const T& _min, const T& _max) { return min(max(x, _min), _max); }

instead of

template <class T>
inline T minmax(T x, T _min, T _max) { return min(max(x, _min), _max); }

which is sort of logically semantics
especially when you consider the other related templates:

template <class T> inline const T& min(const T& a, const T& b) { return a < b ? a : b; }
template <class T> inline const T& max(const T& a, const T& b) { return a > b ? a : b; }

What if min / max for T is defined returning temporary?

Foo min(const Foo& a, const Foo& b);

then you would be returning reference to temporary....

Well, maybe this is not really strong argument as min/max are rarely defined directly - OTOH compilers are really goot at optimizing, so practical differences in code generated are, I believe, unlikely.

That said, proposed change would be nice if type does not have copy.

I am sort of undecided, but current minmax worked fine for 10 years, I guess there is not a strong incentive to change now.

Mirek

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