Are For loops macros possible?
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From: Nobody on 28 Feb 2010 13:00 I am implementing a callback function for multiple callbacks, but the callback function does not have a parameter such as a handle or number to tell which callback the call is for. I have no control over it, so I can't add my own parameters, so I have to provide different entry points that calls a centralized routine with a sequence number. So I have functions like this: int func0(int para1,int para2) { return func(0,para1,para2);}; int func1(int para1,int para2) { return func(1,para1,para2);}; int func2(int para1,int para2) { return func(2,para1,para2);}; int func3(int para1,int para2) { return func(3,para1,para2);}; .... I plan to use a macro like this to generate the above using the Token-Pasting Operator (##): #define paster( n ) int func##n(int para1,int para2) { return func(##n,para1,para2);} So, to generate the above, I would use: paster(0); paster(1); paster(2); paster(3); .... Is there a way to repeatedly call the macro a fixed number of times? Something like #while or #for loop? Currently, I am using an Excel sheet to generate the code. Example: = "paster(" & A1 & ");" Cells A1 to Ann contain sequence numbers filled by Edit-->Fill-->Series, so I only have to do one copy and paste. I am using VC6 and 2003. Thank you
From: Igor Tandetnik on 28 Feb 2010 13:23 Nobody wrote: > I am implementing a callback function for multiple callbacks, but the > callback function does not have a parameter such as a handle or number to > tell which callback the call is for. I have no control over it, so I can't > add my own parameters, so I have to provide different entry points that > calls a centralized routine with a sequence number. So I have functions like > this: > > int func0(int para1,int para2) { return func(0,para1,para2);}; > int func1(int para1,int para2) { return func(1,para1,para2);}; > int func2(int para1,int para2) { return func(2,para1,para2);}; > int func3(int para1,int para2) { return func(3,para1,para2);}; > > I plan to use a macro like this to generate the above using the > Token-Pasting Operator (##): Consider a template instead: template <int seq> int func(int para1, int para2) { return func(seq, para1, para2); } func<2>(42, 84); > #define paster( n ) int func##n(int para1,int para2) { return > func(##n,para1,para2);} You don't need second ##. Drop it. > Is there a way to repeatedly call the macro a fixed number of times? Use the template, and you wouldn't need to. If for some strange reason you insist on using macros, there might be something like this in Boost Preprocessor library: http://www.boost.org/doc/libs/1_42_0/libs/preprocessor/doc/index.html -- With best wishes, Igor Tandetnik With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925
From: Barry Schwarz on 28 Feb 2010 18:43 On Sun, 28 Feb 2010 13:00:59 -0500, "Nobody" <nobody(a)nobody.com> wrote: >I am implementing a callback function for multiple callbacks, but the >callback function does not have a parameter such as a handle or number to >tell which callback the call is for. I have no control over it, so I can't >add my own parameters, so I have to provide different entry points that >calls a centralized routine with a sequence number. So I have functions like >this: > >int func0(int para1,int para2) { return func(0,para1,para2);}; >int func1(int para1,int para2) { return func(1,para1,para2);}; >int func2(int para1,int para2) { return func(2,para1,para2);}; >int func3(int para1,int para2) { return func(3,para1,para2);}; >... > >I plan to use a macro like this to generate the above using the >Token-Pasting Operator (##): > >#define paster( n ) int func##n(int para1,int para2) { return >func(##n,para1,para2);} The preprocessor works on tokens. The purpose of the first ## operator is to concatenate the literal func with the parameter n, resulting in a single token (e.g., func1). What is the purpose of the second ## operator? What would happen if you deleted it? > >So, to generate the above, I would use: > >paster(0); >paster(1); >paster(2); >paster(3); >... > >Is there a way to repeatedly call the macro a fixed number of times? Not in C. >Something like #while or #for loop? Currently, I am using an Excel sheet to >generate the code. Example: > >= "paster(" & A1 & ");" > >Cells A1 to Ann contain sequence numbers filled by Edit-->Fill-->Series, so >I only have to do one copy and paste. > >I am using VC6 and 2003. > >Thank you > -- Remove del for email
From: Nobody on 28 Feb 2010 19:16 "Barry Schwarz" <schwarzb(a)dqel.com> wrote in message news:7chlo5hohjp5c56ij8h68tbvnl106nnsv0(a)4ax.com... > On Sun, 28 Feb 2010 13:00:59 -0500, "Nobody" <nobody(a)nobody.com> > wrote: > >>I am implementing a callback function for multiple callbacks, but the >>callback function does not have a parameter such as a handle or number to >>tell which callback the call is for. I have no control over it, so I can't >>add my own parameters, so I have to provide different entry points that >>calls a centralized routine with a sequence number. So I have functions >>like >>this: >> >>int func0(int para1,int para2) { return func(0,para1,para2);}; >>int func1(int para1,int para2) { return func(1,para1,para2);}; >>int func2(int para1,int para2) { return func(2,para1,para2);}; >>int func3(int para1,int para2) { return func(3,para1,para2);}; >>... >> >>I plan to use a macro like this to generate the above using the >>Token-Pasting Operator (##): >> >>#define paster( n ) int func##n(int para1,int para2) { return >>func(##n,para1,para2);} > > The preprocessor works on tokens. The purpose of the first ## > operator is to concatenate the literal func with the parameter n, > resulting in a single token (e.g., func1). What is the purpose of the > second ## operator? What would happen if you deleted it? I guess I should have used less confusing names. In the example, I have a central function func() to be called by func0(), func1(), func2(), etc. This central function func(), has an additional parameter "int seq", and these "n" functions supply a sequential number to func(). This example maybe illustrate it better: // Central function: Has 3 parameters, the first is sequence number int func(int seq, int para1,int para2) { // Some code }; // "n" functions: Have 2 parameters int func0(int para1,int para2) { return func(0,para1,para2); }; int func1(int para1,int para2) { return func(1,para1,para2); };
From: Nobody on 28 Feb 2010 20:15
"Nobody" <nobody(a)nobody.com> wrote in message news:uUJaDSNuKHA.5940(a)TK2MSFTNGP02.phx.gbl... > // Central function: Has 3 parameters, the first is sequence number In case I wasn't clear enough, the sequence parameter is used to lookup an array of structures representing the corresponding callback. |