How to call function whose function call with arguments is in astring

[grbgooglefan]

Hello,
Can you please enlighten me if we can do this in C++?

I would like to do something like this:
-----------------------------------------------------------------------------------------------------
typedef struct IOParams {
char *ioString;
long lionum;
double dionum;
float fionum;
int nionum;
} *pIOParams;
typedef std::vector<IOParams> ioparm_vector;
ioparm_vector v_ioparams; <---- This will be populated at startup &
may contain any number of elements.

char *strFunctionCmd =
"myfunctionCall("iiisd",v_ioparams[0].nionum,v_ioparams[1].nionum,v_ioparams[2].nionum,v_ioparams[3].ioString,v_ioparams[4].dionum)";

int retstat = call_function_in_string(strFunctionCmd );
-----------------------------------------------------------------------------------------------------
The vector size could vary, but that is not main issues here.
The problem is that even the variable number arguments function cannot
be used here because for those functions also we need to have the
number & type of arguments fixed at compile time and the input
arguments passed to them are individual variables.

In the above case, variables are part of a vector having variable
size, so writing call for that also is difficult.

Is there any way to achieve this in C++?
Any suggestions please?
Thanks in advance for help.

 

[Victor Bazarov]

Hello,
Can you please enlighten me if we can do this in C++?

I would like to do something like this:
-----------------------------------------------------------------------------------------------------
typedef struct IOParams {
char *ioString;
long lionum;
double dionum;
float fionum;
int nionum;
} *pIOParams;
typedef std::vector<IOParams> ioparm_vector;
ioparm_vector v_ioparams; <---- This will be populated at startup &
may contain any number of elements.

char *strFunctionCmd =
"myfunctionCall("iiisd",v_ioparams[0].nionum,v_ioparams[1].nionum,v_ioparams[2].nionum,v_ioparams[3].ioString,v_ioparams[4].dionum)";

int retstat = call_function_in_string(strFunctionCmd );
-----------------------------------------------------------------------------------------------------
The vector size could vary, but that is not main issues here.
The problem is that even the variable number arguments function cannot
be used here because for those functions also we need to have the
number & type of arguments fixed at compile time and the input
arguments passed to them are individual variables.

In the above case, variables are part of a vector having variable
size, so writing call for that also is difficult.

Is there any way to achieve this in C++?
Any suggestions please?

Take a look at 'boost::any' and 'boost::smart_ptr'. You can have
a vector of any type, essentially, and pass it into your function.
It is entirely possible I've missed the point of your inquiry
altogether, sorry, then.

V

 

[Pascal Bourguignon]

Hello,
Can you please enlighten me if we can do this in C++?

I would like to do something like this:
-----------------------------------------------------------------------------------------------------
typedef struct IOParams {
char *ioString;
long lionum;
double dionum;
float fionum;
int nionum;
} *pIOParams;
typedef std::vector<IOParams> ioparm_vector;
ioparm_vector v_ioparams; <---- This will be populated at startup &
may contain any number of elements.

char *strFunctionCmd =
"myfunctionCall("iiisd",v_ioparams[0].nionum,v_ioparams[1].nionum,v_ioparams[2].nionum,v_ioparams[3].ioString,v_ioparams[4].dionum)";

int retstat = call_function_in_string(strFunctionCmd );
-----------------------------------------------------------------------------------------------------
The vector size could vary, but that is not main issues here.
The problem is that even the variable number arguments function cannot
be used here because for those functions also we need to have the
number & type of arguments fixed at compile time and the input
arguments passed to them are individual variables.

In the above case, variables are part of a vector having variable
size, so writing call for that also is difficult.

Is there any way to achieve this in C++?
Any suggestions please?
Thanks in advance for help.

You may use ffcall to build a call stack at run-time.
http://www.haible.de/bruno/packages-ffcall.html

--
__Pascal Bourguignon__ http://www.informatimago.com/

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