Exception is not handled when opening fstream

Question

Context

I have this simple code:

#include <iostream> #include <fstream> #include <system_error> int main(int argc, char *argv[]) { std::ifstream file; file.exceptions(std::ios::failbit | std::ios::badbit); try { file.open("a_file_does_not_exist.txt", std::ios::in); file.close(); } catch(const std::ios_base::failure& err) { std::cerr << err.code() << std::endl; return -1; } return 0; } 

Just to complete, this is a compilation command:

  g++ -std=c++11 -g // ... 

G ++ Compiler Version (GCC) 6.1.1.

Platform: arch-linux 4.7.2-1.

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Problem

As you can imagine, the file does not exist, therefore the file.open(...) method file.open(...) an exception. The problem is that when I run the code, the exception is not handled and std::terminate called.

The strange thing is the result:

 terminate called after throwing an instance of 'std::ios_base::failure' what(): basic_ios::clear Annullato (core dump creato) 

As you can read, the throwing class is std::ios_base::failure , but my catch is right in this class.

My question is: what am I missing?

Answer 1

Why don't you just use file.good() and file.fail() to handle exceptions. This will work just fine for what you are trying to do.