Re: return value optimization vs. returning a boost::shared_ptr of container

"Bo Persson" <>
Wed, 16 Jun 2010 08:01:29 CST
{ note to moderators redacted. -mod }

Daniel Kr?gler wrote:

On 15 Jun., 21:59, Jeff Flinn <> wrote:

Goran wrote:


I think so, too, but you have swap method, which is efficient. So:

LibMapType map;

IIRC, that won't compile on gcc 4.0.1 for me(but does with MSVC's
extensions). I need to:

LibMapType map;

Yeah, this is the only correct way, because swap requires a
(mutable) lvalue, but above an rvalue was provided. It is a
shame, that accepting rvalues at these locations still belong
to the default settings of MSVC...

Who runs compilers with default settings? :-) Those are permissive
enough to minimize the number of support cases for the product. A
business optimization.

If we compile with the proper setting - highest warning level - the
compiler will tell us that "the type conversion is not allowed by the
C++ standard".

Bo Persson

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