Dean wrote:
I've recently tried the following (inlined test) which isolates the problem I've encountered with boost::lexical_cast<int8_t>:
#include <iostream> #include <boost/lexical_cast.hpp>
int main(int argc, char * argv[]) { int8_t value; try { value = boost::lexical_cast<int8_t>("127"); } catch (std::exception & e) { std::cerr << e.what() << '\n'; } return 0; };
This is compiled with gcc 4.1.2 on Linux. Any idea why 127 wouldn't fit into an 8-bit signed integer? The defined range for signed 8 bit integers should be -127..+127 right?
Hi Dean, You haven't said what you expected to happen and what happened instead. So here's a guess: you expect int8_t to be treated as an integer by lexical_cast. It isn't; despite the name, it's a character; you are asking it to convert a string to a character. (Try some other strings where you have "127". I think it will reject anything with more than one character in it.) I have previously suggested that this behaviour should change, but the opinion of the list has been that using int8_t probably indicates "over-optimised code", and that the feature can be easily worked around with some additional casts. In this case, I suggest that you lexical_cast to int, do a bounds check yourself (if necessary) and then assign to the int8_t. Regards, Phil.