Expert: vijayan - 4/6/2010

Question
I want to evaluate string expression in if stmt.
E.g.
int i = 0,j = 2;
char * str = "(i == 0) || (j == 2)";

if(str) /* This should execute code within if condition*/
{
...
}

Answer
You will need to write a mini parse to recognize and evaluate the sequence of characters in the string as an expression belonging to some grammar.

Perhaps use a parser library to do this; for example Spirit which is part of Boost.
http://www.boost.org/doc/libs/1_37_0/libs/spirit/classic/index.html