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http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0811r2.html

> The standard alternative

> a+(b-a)/2

> works for unsigned integers (even if b<a).

This is wrong. It work only if "b >= a".

You can use "(a >> 1) + (b >> 1) + (a & b & 0x1)" if both number is signed
this was patended by Samsung, but patent expired, see
https://stackoverflow.com/a/3816473 https://patents.google.com/patent/US6007232

or "std::min(a,b)+(std::max(a,b)-std::min(a,b))/2"

https://rise4fun.com/Z3/tVfo checked using SMT solver

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<div dir=3D"ltr">http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0=
811r2.html<br><br>&gt; The standard alternative<br><br>&gt; a+(b-a)/2<br><b=
r>&gt; works for unsigned integers (even if b&lt;a). <br><br>This is wrong.=
 It work only if &quot;b &gt;=3D a&quot;.<br><br>You can use &quot;(a &gt;&=
gt; 1) + (b &gt;&gt; 1) + (a &amp; b &amp; 0x1)&quot; if both number is sig=
ned<br>this was patended by Samsung, but patent expired, see https://stacko=
verflow.com/a/3816473=C2=A0https://patents.google.com/patent/US6007232<div>=
<br>or &quot;std::min(a,b)+(std::max(a,b)-std::min(a,b))/2&quot;<br><br>htt=
ps://rise4fun.com/Z3/tVfo checked using SMT solver</div></div>

<p></p>

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