"Scoping" variables the middle of their "natural" scope - RAII - is it a good practice?
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From: Mathias Gaunard on 16 Jan 2010 20:18 On 16 jan, 19:25, ManicQin <manic...(a)gmail.com> wrote: > When looking on projects and examples in the internet I find more and > more "scoped" classes (RAII), > ScopeGuard, ScopedTimer, ScopedBarrierEnd ,ScopedForking , auto_ptr > (and his many friends) and the list is long... > > Now, when dropping the "re-scoping" of a class I can harm the - > logical- flow of the code. I fail to see how freeing some resources later than you could -- which is what it means by removing the localized scope some RAII handlers are in -- harms the logical flow of the code. -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: Nick Hounsome on 18 Jan 2010 00:28
On 16 Jan, 19:25, ManicQin <manic...(a)gmail.com> wrote: > Hello everybody, > Let me explain what I mean, > > In my job I find many times the next "pattern" > > void foo() > { > //some code > { //"re-scoping" > char sTmp[256] = ""; > //some code > } > //some code > > } Even without dtors there is a big difference between { char sTmp1[256] = ""; // arrays on the stack is a very bad idea anyway! //stuff } { char sTmp2[256] = ""; //stuff } and the same without brackets. Even a poor compiler knows that this only needs 256 bytes of stack whereas a poor one might reserve 512 for an unbracketed version. -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] |