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From: Giovanni Dicanio on 9 May 2010 04:17 "RB" <NoMail(a)NoSpam> wrote: Just a couple notes: > I put the > #include <vector> > #include <iostream> I would suggest to put these #include's in "StdAfx.h" (precompiled headers). > using namespace std; In a real-world project, instead of 'using namespace std', I would just use std::vector. I think importing the whole std:: namespace is OK in simple test code, but not in real-world apps. HTH, Giovanni
From: RB on 9 May 2010 08:43 Hey Joe, actually I did post the error msgs along with the corresponding code but it was a few threads back up. I did not post the entire class if that is what you mean. In any case what was confusing me was that I had no errors until I posted the vector samples and then I would. But as previously posted I have rectified that and have started to increment the application now in a new project. Thanks always for all the help you give me even though I may not post conducively always.
From: RB on 9 May 2010 08:52 >In a real-world project, instead of 'using namespace std', I would just use std::vector. I think importing the whole std:: >namespace is OK in simple test code, but not in real-world apps. Thanks and if you would comment further on these: I have read that putting using namespace std in the include file "bloats" the application. But putting it in a cpp file only affects that cpp file of the app. What exactly does this mean. I have never really gotten under the namespace thing but I thought it was something similar in concept to a define. Also I have always wondered when you include an include file, it only adds "referenced" items to app from the includes, correct? In other words it doesn't add the entire include code to your app, correct ?
From: Joseph M. Newcomer on 9 May 2010 13:06 You did not indicate that the error messages you reported were the SAME error messages as cited in the previous message; you left us with the impression that these were a new set of errors. joe On Sun, 9 May 2010 08:43:18 -0400, "RB" <NoMail(a)NoSpam> wrote: >Hey Joe, actually I did post the error msgs along with the >corresponding code but it was a few threads back up. >I did not post the entire class if that is what you mean. > In any case what was confusing me was that I had >no errors until I posted the vector samples and then >I would. But as previously posted I have rectified that >and have started to increment the application now in >a new project. >Thanks always for all the help you give me even though >I may not post conducively always. > > > Joseph M. Newcomer [MVP] email: newcomer(a)flounder.com Web: http://www.flounder.com MVP Tips: http://www.flounder.com/mvp_tips.htm
From: Joseph M. Newcomer on 9 May 2010 13:21
See below... On Sun, 9 May 2010 08:52:01 -0400, "RB" <NoMail(a)NoSpam> wrote: > > >>In a real-world project, instead of 'using namespace std', I would just use std::vector. I think importing the whole std:: >>namespace is OK in simple test code, but not in real-world apps. > >Thanks and if you would comment further on these: >I have read that putting >using namespace std >in the include file "bloats" the application. **** I fail to see how qualifying a namespace can "bloat" an application. I am not sure what you read that suggests this, but a namespace is merely syntactic directive to the compiler, and generates no code. **** >But putting it in a cpp file >only affects that cpp file of the app. >What exactly does this mean. *** As I said, I have no idea what this could possibly mean, since the notion of a syntactic directive "bloating" an application seems inherently nonsensical. **** >I have never really gotten under the >namespace thing but I thought it was something similar in concept >to a define. **** No, it is a directive to C++ that tells it that when it has an unqualified name, it first checks local scope, then class scope, then the selected namespaces, then the global namespace. I'm not sure if there is a defined order to the namespace searches, or it is left up to the compiler writer to determine the order, and I don't want to look it up right now. But "bloat" is one of those nonsensical terms (like "crash") that seems to have meaning but is largely nonsensical (for example: if you have code that is actually callable, and does something, it is not "bloat", it is "part of the functionality of the program". An unholy fascination with code size is the mark of a beginner ("What's wrong with Windows? I did "hello world" and got <explanation of meaningless numbers follows> but in Unix it is only <equally meaningless comparison of meaningless numbers>" as if .exe file size, process address space size, or any other meaningless metric had relevance for modern programming. But attributing "using namespace" to causing "bloat" sounds to me like total nonsense. **** > >Also I have always wondered when you include an include file, >it only adds "referenced" items to app from the includes, correct? >In other words it doesn't add the entire include code to your app, >correct ? **** No, it substitutes the text of the included file, period. It is as if you had replaced the #include with a copy-and-paste of the contents of the file. Nothing more, and nothing less. If you have a header file that includes a million bytes of code, every compilation gets a million bytes of code. But that would just be poor programming. Note that the LINKER can drop subroutines that are not called, but this is not the role of the compiler. Note that 'using namespace' does NOT generate any code, so claiming it can "bloat" an application is nonsense. And it does not make the runtime symbol table any larger, because the runtime symbol table is going to be the same size whether you declare a 'using namespace' or not. All the 'using namespace' declaration changes is the rules for how that symbol table is searched! Personally, I find 'using namespace std' to be an excuse for lazy programmers to not type std:: ahead of what should be qualified names. I always type std:: in front of any component of the std:: namespace; it is a better form of documentation, does not result in ambiguities, and overall makes it more obvious to future maintainers what is going on. But it cannot make your app bigger by using it. joe **** > Joseph M. Newcomer [MVP] email: newcomer(a)flounder.com Web: http://www.flounder.com MVP Tips: http://www.flounder.com/mvp_tips.htm |