Hi Vladimir, "Vladimir Prus" <ghost@cs.msu.su> wrote in message news:c53i71$4gs$1@sea.gmane.org...
In fact,
using assignment::operator<<
does not have this problem, though it's cumbersome.
it had with my compilers.
Hmm... strictly speaking,
using assignment::operator<<;
should make this operator because as if it's declared in namespace where "using" appears, as far as name hiding is concerned.
you're right. I had a global using declaration. I'm still a bit confused, though.
true, but the compiler is not forced to inline it. So unless you are
talking about requiring linking, I don't get it.
The point is: making the function 'inline', either with explicit keyword or by placing it in the class body *increases* the chances that it will be inlined. And since inlining here can cause code bloat, it's better not to increase those chances.
I agree I should investigate how my lib perform in this regard. I do think that we wan't all the inlining that we can get. For example, vector<int> v; v += 1,2; should preferably be expanded to vector<int> v; v.push_back( 1 ); v.push_back( 2 ); I don't see any benefit of another layer of function-calls (except larger code size:-)).
I've just sketched an example which can be found at
http://zigzag.cs.msu.su:7813/inline
There are two files -- one with in-class definition and one with out-of-class definition. Both are compiled with -O3 but the function is inlined only in the first example and the number of instructions needed to each call grows from 4 to 13. In a real example the difference might be smaller, but it also might be larger :-(
with vc7.1 and como4.3 the results are: -rwxrwxrwx 1 nesotto None 135168 Apr 9 00:12 cl_inline.exe -rwxrwxrwx 1 nesotto None 135168 Apr 9 00:08 cl_inline2.exe -rwxrwxrwx 1 nesotto None 950272 Apr 9 00:07 como_inline.exe -rwxrwxrwx 1 nesotto None 950272 Apr 9 00:08 como_inline2.exe
It was some time ago, so situation might have improved in gcc or in libstdc++, but generally, unnecessary inlining will still increase the code size.
perhaps; except when it decreases code size. :-) Arguable it would be good to see more what other compilers do; and I would like to see your code optimized for size (-O3 is for speed, right). br Thorsten