I tried to compile a source code package, and found version-specific issues.
When I do that on my computer, everything goes well; but when I compile it on another computer, it produces a lot of claims that INT32_MAX is not defined. Both computer runs a Debian system, and the difference is my computer uses Testing repo and has gcc 4.9, and the other computer uses Stable repo., which has slightly older gcc 4.7.
Then I have a detailed look inside /usr/include/stdint.h. By surprise, on the computer claiming the undefined macros, all int range macros are defined inside a non-C++ condition:
/**
* I forget the exact definition,
* but it looks like this:
*/
#ifndef __cplusplus ......
......
# define INT32_MIN XXX
# define INT32_MAX XXX
......
#endif
As a result, the package won't see these standard range macros, as it is a C++ project, and uses g++ to compile.
Why the stdint.h of gcc 4.7 is designed like this? Is that means gcc 4.7 don't want me to use those integer ranges with C++, and gcc 4.9 allows it?
And the most important: how should I work around this?
In C++ you're recommended to use std::numeric_limits #include <limits>:
Usage example from cplusplus.com
// numeric_limits example
#include <iostream> // std::cout
#include <limits> // std::numeric_limits
int main () {
std::cout << std::boolalpha;
std::cout << "Minimum value for int: " << std::numeric_limits<int>::min() << '\n';
std::cout << "Maximum value for int: " << std::numeric_limits<int>::max() << '\n';
std::cout << "int is signed: " << std::numeric_limits<int>::is_signed << '\n';
std::cout << "Non-sign bits in int: " << std::numeric_limits<int>::digits << '\n';
std::cout << "int has infinity: " << std::numeric_limits<int>::has_infinity << '\n';
return 0;
}