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Re: Defs.h minmax() change/fix [message #25373 is a reply to message #25325]

Fri, 19 February 2010 16:52

mirek
Messages: 14256
Registered: November 2005

Ultimate Member

kohait00 wrote on Wed, 17 February 2010 04:24

yiy are right, the compiler warns
warning C4172: returning address of local variable or temporary

using a

s = min(max(a, b), c);

//instead of

s = minmax(a, b, c);

does not produce this warning. i still dont get why.

maybe to have a

#define minmax(x, _min, max) min(max(x, _min), _max)

is a choice.

or at least

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

reducing the need of object copy by 60% Smile

(roughly)

dont know it this is that much of speed saving, but using refs instead of temp copies is better anyway, isnt it?

In this case, I believe there will be no difference in code generated in most cases. It is inline after all. And in fact, it is used on fundamental types 90% of time.

Mirek

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