Apparently different behaviour assigning C string to std::string, for Relese/Debug

[piul]

Hi, I think I'm getting different behaviours with the code below for Release and Debug compiles.

FILE* in ;
err = fopen_s (&in, fileName.c_str(), "r");
if (!in) {
std::cerr << "cannot open input file '" << fileName << "'" << std::endl;
return;
}
char buff[1024];
while (fgets(buff, 1024, in)) {

std::string line=buff;

//...

line is getting the characters ok when compiled in Debug. In Release though, line is BadPtr. I guess I'm doing the initialization wrong, but I don't see why.

[jeron1]

Perhaps this[^] link will help.

"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment "Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst

[Lost User]

I suspect there is something you are not showing us. I have just tried your code and it works in both Debug and Release modes.

[_Superman_]

It's possibly a configuration issue. Meaning you've some configuration for Debug that you haven't done for Release.

«_Superman_»  _I love work. It gives me something to do between weekends.

_Microsoft MVP (Visual C++) (October 2009 - September 2013)

Polymorphism in C

[piul]

My excuses for not answering during the weekend. As suggested by some comment on the link you posted (thank you) the problem seems to be in the fgets function. It is storing senseless data in buff for Release, and then the std::string constructor can't make sense of it. I will try with std::getline().

[piul]

It is, quite probably. fgets (not std::string constructor as I initially posted) is behaving different if I set different options for Optimization and Runtime Library in MSVS2005. I can't make Release work like Debug though, even setting the same options.