So don't you think that at compile time it's obvious for the compiler to create a "compile-time boxed version of the constant", thus no boxing at all at run time (what I've called "object(1)", below) ? It is really a trivial optimization taught at most compilation courses - I would expect to think most compilers would implement it.
Igal Yoffe > -----Original Message----- > From: Discussion of advanced .NET topics. > [mailto:[EMAIL PROTECTED] On Behalf Of > Richard Blewett > Sent: Tuesday, August 07, 2007 11:09 AM > To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM > Subject: Re: [ADVANCED-DOTNET] compiler considerations > > This will always cause one box operation. The version of > WriteLine that will be called will be the one with the signature > > WriteLine(string format, params object[] args); > > Therefore all the args will be treated as object - this means > the 1 will be boxed. However, the second argument due to > operator precedence will create the struct, and call its > ToString method. The compiler knows exactly which ToString > method must be called - if MyStruct overrides ToString then > it will be the MyStruct version if not it will be > System.Object's version - therefore, no virtual dispatch is > required and therefore no boxing. > > Regards > > Richard Blewett - DevelopMentor > > > -----Original Message----- > > From: Discussion of advanced .NET topics. [mailto:ADVANCED- > > [EMAIL PROTECTED] On Behalf Of Igal Yoffe > > Sent: 07 August 2007 08:20 > > To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM > > Subject: [ADVANCED-DOTNET] compiler considerations > > > > Consider the following code: > > Console.Writeline("{0} {2}",1,(new MyStruct()).ToString()); > > > > The number of boxings in such code is between 0 to 2, > depending on the > > implementation of the compiler. > > > > Straightforwardly, two boxings are obvious, viz., int boxing and > > struct's boxing before calling ToString. However, it could > be the case > > that in compile time the compiler creates "object(1)" (really a > > trivial > > optimization) for the integer, and moreover have special > vtable logic > > for structures (recall that structures could not be > inherited) which > > calls ToString directly, thus no boxings at all. > > > > While I could examine the ilasm generated by _my_ compiler > I would be > > really glad to know what do you think _typical_ (e.g. > microsoft's csc) > > compiler would do? > > > > =================================== > > This list is hosted by DevelopMentorR http://www.develop.com > > > > View archives and manage your subscription(s) at > > http://discuss.develop.com > > =================================== > This list is hosted by DevelopMentor(r) http://www.develop.com > > View archives and manage your subscription(s) at > http://discuss.develop.com > =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
